Let's talk types.
First of all, I can confidently say Fire is the second worst type in RBY. While Fighting is weak to Psychic, at least it has a useful resistance to Rock and actually has a niche in being the only type to smack Normal Super Effectively. Fire doesn't have this trait. All of its resistances are kind of lame (Bug, Grass, and Fire) and not that common as offensive typings, the most common one being Grass. Meanwhile it weak to almost all the common offensive typings - Water, Rock, and Ground. And that's terrible. It's not even the offensive typing we knew it as - It only hits Bug, Grass, and Ice SE. Mono-Fire is terrible.
Fighting is also pretty bad, but its only situationally bad. The only reason Fighting is considered awful is because of its weakness to the best type in the game. It still hits not only Normal-types but also Rock-types SE. Ice is also nice, but those two are much more important. I wouldn't want to be a Fighting-type, but if I was it wouldn't be all bad - at least I'd get STAB on Submission. Meanwhile, Poison (The absolute worst type in the game, sadly ;_;) is just plain awful. Funnily enough, it's basically a worst Fire and objectively a worst Ghost. Offensively it does everything Fire does but worst (doesn't hit Ice, resisted by 4 common types vs Fire's 3). Meanwhile, it's only claim to fame is the resistance to Fighting...which is done better by Ghost (I'd argue Bug too but most new Fighting-types have Rock Slide iirc.). Also its best STAB is Sludge, so even if it was a good offensive typing (its not) it would have a shitty base 65 STAB that not even every poison-type gets. The cherry on top of the shit sundae though is that weakness to Psychic, sealing the deal on its placement as the worst typing.
Bug is kind of weird. It would be a great typing offensively due to its niche of hitting Psychics Super Effectively, except the best Bug STAB is Pin Missle, which not even all Bugs get. Defensively though it's not awful. Its Ground resistance is neat, although Rock Slide on Ground-types is now common, but they are unSTAB'd and the Ground resist is still nice overall, especially if you're Rock / Bug. Fighting resist is actually not that terrible, as Submissions are going to be thrown around. Psychic does it better but Psychic doesn't resist Ground as well so its a plus. Grass resist isn't notable - everything resists Grass. While it does have 4 weaknesses, only 2 really matter - Flying and Rock (Poison and Fire don't). And Flying isn't even that bad, since the best STAB Flying has is Drill Peck which, again, not all Flying-types have. So really the most important one is Rock. Not bad, Bug. However, I still think mono-Bug is kind of mediocre due to no good STAB and its resists kind of failing it when you see those weaknesses. It's much better as a secondary type to something like Rock / Bug. Still, Mono-Bug isn't bad - just kind of underwhelming. Also keep in mind no STAB =/= no good offensive presence. Look at Gengar.
Let's keep on the typings with no good STAB - Ghost is really fucking good. It has immunities to the 2nd best typing in the game and Fighting, which would be the perfect 2 move coverage with Normal if Ghost didn't exist. It's poison resist is not notable in the slightest but its there. It also has no Weakness! Ok that's technically wrong - its weak to Ghost. However, a problem with Ghost is also a great boon. The only attacking Ghost moves are Night Shade (a Seismic Toss clone) and Lick, which is fucking Lick. Even a Super Effective Lick is weaker than most neutral moves. So essentially Ghost has no weaknesses. Offensively its bad obviously - even if it did have a good STAB the only thing it hits is Ghost while the two best types in the game are flat-out immune. Mono-Ghost can work as a defensive typing, especially if it got on something with high bulk (like, say, 120/120/120 bulk. Wink Wink)
Dragon is in a similar boat to Ghost - great defensive typing, would be great offensive typing. Dragon Rage is a shitty move, and the only Dragon-type move period. However, it has good resistances in Electric and Water (Grass is alright, and Fire is lol), and it only has one weakness in Ice. Works much better as a combo type but mono Dragon isn't awful. Not much else to say here.
Grass gets walled by fucking everything (6 resists and 4 that really matter), and has a ton of weaknesses. What keeps Grass floating offensively is niches, mainly its countering abilities to Water. Offensively it hits Rock and Grounds SE and (much more importantly) Water. Meanwhile it also resist Water, making it a decent enough answer to Water. Well, except most of them get Ice Beam, but shh. While it has 5 weaknesses, only 2 matter (weakness to Bug, Fire, and Poison are mostly irrelevant.) - Ice and Flying, and again with Bug Flying only kind of matters. Yet again like Bug though, that Ice weakness hurts it a lot due to it being common coverage on the things it wants to wall. Defensively, its resist are pretty good - Electric, Water and Ground are pretty good. Grass is...eh.
I'm too lazy to do the rest right now, but I do think the rest are good typings (yes, even Ice. I should probably do a paragraph on Ice later)