Let's face it, SR has 3 resistances (types), and 4 weaknesses (types).
Steel, Ground, and Fighting are the 3 types which resist it, and they are very common in OU. Especially the ever-common Lucario whom is 4x resistant to SR (as is Steelix, but it is not OU).
Ice, Fire, Flying, and Bug are the 4 types which are weak to it, and the first two are very uncommon in OU.
In addtion, either Steel or Fighting accompany the only 2 Fire types in OU- Infernape and Heatran, effectively making them nuetral to Stealth Rock.
Furthermore, either Steel or Fighting also accompany 3/5 of the only Bug types in OU- Scizor, Forretress and of course Heracross.
Granted the only 2 other Bug types in OU are 4x weak to SR- Ninjask and Yanmega, so there is something to make-up for the other 3 nuetral Bugs, but still these 2 are much less popular (Baton pass Teams in General are less popular in the faster paced DP), or are almost always leads.
Ice is also a very rare type in OU- Only Weavile, Mamoswine, and Abamasnow are popular in DP. Additionally, Weavile and Abamasnow (for its ability, rather than wekaness) are common leads, while Mamoswine is only nuetral to SR because it is part Ground.
Therefore, 1/3 of the OU Ice types are nuetral to SRock, and the other 2 are commonly used as Leads.
I must also point out that the only 4x weak to Stealth Rock Ice type (Articuno) is a Border Line pokemon, rather than a UU pokemon, where SR is even more common in UU. Keep in Mind that Jynx is UU (And has 361 Base Special Attack when Modest), so don't simply say Articuno is simply too strong for BL. So if one were to say that Articuno isn't used for its 4x weakness, then why isn't it's usage down to UU, where it would literally be "Underused"?
Now, here is where the value of SR kicks in, on its last effective type: Flying.
Flying is quite common in OU: Salamence, Zapdos, Gyarados, Dragonite, Togekiss, Skarmary, and Gliscor.
(If you are thinking about Crobat, Moltres, Aerodactyl, Charizard, and Staraptor then you forgot they are BL, not OU, furthermore, if you feel Charizard is not OU simply b/c of SR alone, keep in mind it can actually take advantage of SR and use its Belly Drum set without needing to use Substitute to activate Blaze and Salac, potentially giving Charizard assistance rather than deterance from switchin in).
So with 7 OU flying types, Flying is the most common type weak to SR, but keep in mind the last 2 (Skarmary and Gliscor) are actually nuetral to SR because they are either part Steel, or part Ground, leaving only 5 OU Flying types weak to SR.
Keep in mind Skarmary and Gliscor are probably 2 of the most used OU Flying types in D/P as they are the most used Physical walls in the game.
Additionally, Dragonite is not seen very often, so in a way, there are only 4 common Flying types weak to SR in OU (Gyarados, Salamence, Zapdos, and Togekiss), and that the last 3 of these Flying types all have access to at least 1 healing move; Roost.
So, let's take a look at the Pokemon in TOTAL weak to Stealth Rock in OU:
Fire- 0
Bug- 2 (Ninjask and Yanmega)
Ice- 2 (Weavile and Abamasnow)
Flying- 5 (Salamence, Gyarados, Zapdos, Togekiss, and Dragonite).
So out of all OU pokemon only 9 are weak to SR, and 6 of those 9 (Ninjask, Yanmega, Weavile, Abamasnow, Salamence, Gyarados) are commonly used as leads, meaning their first-turn-use is never affected by SR.
Additionally, Dragonite is rarely seen in OU, so it, in a sense at least, feels like there are only 8 OU pokemon weak to SR.
Let's for a minute take a look at the Ability Levitate. Just like Flying Types, Pokemon with Levitate are Immune to Spikes, Toxic Spikes, and Ground attacks, but unlike Flying types, they are not necessarily weak to Ice, Electric, nor Rock.
In fact, some Levitating pokemon are used in the place of Flying types to avoid a Weakness (or even to avoid a Nuetrality) to Stealth Rock, while maintaining their benefits:
examples include-
Gengar over Zapdos- Alternative Special Sweeper
Azelf over Zapdos- Alternative Special Sweeper
Azelf over (Nasty Plot) Togekiss- Alternative Special Sweeper
LO Flygon over LO Salamence- Alternative EQ/Spikes/TSpikes Immune Dragon. (LO Flygons usually pack Dragon Claw/EQ/Fire Blast/Roost, plus Flygon is resistant to SR).
Bronzong/Claydol over Gliscor/Skarmary- Alternative SR set-upper/Tank. (Bronzong does get Rest/Talk)
Sometimes Ground, Fighting or Steel types are also used in place of OU Flying/Bug/Ice types:
Garchomp may be used over Salamence or Dragonite
Magnezone over Zapdos (plus Magnezone does get Electrolevitate which gives it an immunity to EQ for 5 turns, which lets it catch up to Zapdos in a way of being a rare electric type immune to EQ)
LO Lucario/Metagross over Gyarados as a physical Sweeper
Hippowdon over Abamasnow to change the weather.
ETC.
My question is, Can Spikes and/or Toxic Spikes be good without SRock?
Remember with only 7 Flying types weak to SRock, doesn't spikes seem more beneficial? 1 Layer hits for the same as neutral SRock, and while it misses FLying/Levitate pokemon, it does hit Steels/Fighting/Ground types for 12%, (and the same can be said for Toxic Spikes, barring Steel/Poison Types).
Spikes, unlike SRock, can also be stacked, and if more layers are down, always do 18%-25%.
Discuss its use, its need and the worthiness of SR.
Steel, Ground, and Fighting are the 3 types which resist it, and they are very common in OU. Especially the ever-common Lucario whom is 4x resistant to SR (as is Steelix, but it is not OU).
Ice, Fire, Flying, and Bug are the 4 types which are weak to it, and the first two are very uncommon in OU.
In addtion, either Steel or Fighting accompany the only 2 Fire types in OU- Infernape and Heatran, effectively making them nuetral to Stealth Rock.
Furthermore, either Steel or Fighting also accompany 3/5 of the only Bug types in OU- Scizor, Forretress and of course Heracross.
Granted the only 2 other Bug types in OU are 4x weak to SR- Ninjask and Yanmega, so there is something to make-up for the other 3 nuetral Bugs, but still these 2 are much less popular (Baton pass Teams in General are less popular in the faster paced DP), or are almost always leads.
Ice is also a very rare type in OU- Only Weavile, Mamoswine, and Abamasnow are popular in DP. Additionally, Weavile and Abamasnow (for its ability, rather than wekaness) are common leads, while Mamoswine is only nuetral to SR because it is part Ground.
Therefore, 1/3 of the OU Ice types are nuetral to SRock, and the other 2 are commonly used as Leads.
I must also point out that the only 4x weak to Stealth Rock Ice type (Articuno) is a Border Line pokemon, rather than a UU pokemon, where SR is even more common in UU. Keep in Mind that Jynx is UU (And has 361 Base Special Attack when Modest), so don't simply say Articuno is simply too strong for BL. So if one were to say that Articuno isn't used for its 4x weakness, then why isn't it's usage down to UU, where it would literally be "Underused"?
Now, here is where the value of SR kicks in, on its last effective type: Flying.
Flying is quite common in OU: Salamence, Zapdos, Gyarados, Dragonite, Togekiss, Skarmary, and Gliscor.
(If you are thinking about Crobat, Moltres, Aerodactyl, Charizard, and Staraptor then you forgot they are BL, not OU, furthermore, if you feel Charizard is not OU simply b/c of SR alone, keep in mind it can actually take advantage of SR and use its Belly Drum set without needing to use Substitute to activate Blaze and Salac, potentially giving Charizard assistance rather than deterance from switchin in).
So with 7 OU flying types, Flying is the most common type weak to SR, but keep in mind the last 2 (Skarmary and Gliscor) are actually nuetral to SR because they are either part Steel, or part Ground, leaving only 5 OU Flying types weak to SR.
Keep in mind Skarmary and Gliscor are probably 2 of the most used OU Flying types in D/P as they are the most used Physical walls in the game.
Additionally, Dragonite is not seen very often, so in a way, there are only 4 common Flying types weak to SR in OU (Gyarados, Salamence, Zapdos, and Togekiss), and that the last 3 of these Flying types all have access to at least 1 healing move; Roost.
So, let's take a look at the Pokemon in TOTAL weak to Stealth Rock in OU:
Fire- 0
Bug- 2 (Ninjask and Yanmega)
Ice- 2 (Weavile and Abamasnow)
Flying- 5 (Salamence, Gyarados, Zapdos, Togekiss, and Dragonite).
So out of all OU pokemon only 9 are weak to SR, and 6 of those 9 (Ninjask, Yanmega, Weavile, Abamasnow, Salamence, Gyarados) are commonly used as leads, meaning their first-turn-use is never affected by SR.
Additionally, Dragonite is rarely seen in OU, so it, in a sense at least, feels like there are only 8 OU pokemon weak to SR.
Let's for a minute take a look at the Ability Levitate. Just like Flying Types, Pokemon with Levitate are Immune to Spikes, Toxic Spikes, and Ground attacks, but unlike Flying types, they are not necessarily weak to Ice, Electric, nor Rock.
In fact, some Levitating pokemon are used in the place of Flying types to avoid a Weakness (or even to avoid a Nuetrality) to Stealth Rock, while maintaining their benefits:
examples include-
Gengar over Zapdos- Alternative Special Sweeper
Azelf over Zapdos- Alternative Special Sweeper
Azelf over (Nasty Plot) Togekiss- Alternative Special Sweeper
LO Flygon over LO Salamence- Alternative EQ/Spikes/TSpikes Immune Dragon. (LO Flygons usually pack Dragon Claw/EQ/Fire Blast/Roost, plus Flygon is resistant to SR).
Bronzong/Claydol over Gliscor/Skarmary- Alternative SR set-upper/Tank. (Bronzong does get Rest/Talk)
Sometimes Ground, Fighting or Steel types are also used in place of OU Flying/Bug/Ice types:
Garchomp may be used over Salamence or Dragonite
Magnezone over Zapdos (plus Magnezone does get Electrolevitate which gives it an immunity to EQ for 5 turns, which lets it catch up to Zapdos in a way of being a rare electric type immune to EQ)
LO Lucario/Metagross over Gyarados as a physical Sweeper
Hippowdon over Abamasnow to change the weather.
ETC.
My question is, Can Spikes and/or Toxic Spikes be good without SRock?
Remember with only 7 Flying types weak to SRock, doesn't spikes seem more beneficial? 1 Layer hits for the same as neutral SRock, and while it misses FLying/Levitate pokemon, it does hit Steels/Fighting/Ground types for 12%, (and the same can be said for Toxic Spikes, barring Steel/Poison Types).
Spikes, unlike SRock, can also be stacked, and if more layers are down, always do 18%-25%.
Discuss its use, its need and the worthiness of SR.