[Garud]

Originally Posted by Fat Nope

Pikachu- High Tier
Availability- Pretty rare in Viridian Forest, but plentiful in the Power Plant later on in the game.
Stats- Base stats of 90 in attack and special attack allow for it to make a dent with any attack. 100 speed lets this thing hit fast and hard coping for its poor HP and defense. 80 special defense works out nicely too, as a Raichu that is.
Typing- Electric. Useful at almost every single point in the game. Only weak to ground attacks, which can be avoided with a flying type. Having an electric type makes much of the game easy from beginning to end with so many water and flying types around.
Movepool- Let's just start with learning thunderbolt at level 26. Early and powerful, which is perfect. It learns thunderwave naturally at level 8 which helps for battle and catching wilds. Dig and brick break counter all the rock/ground foes that fight against it.
Reccomended final moveset- Thunderbolt, Thunderwave, Strength/Dig, Brick Break
Major Battles:
Rival 1- Takes down Pidgey easy, and Squirtle if you chose Charmander. Forced into quick attack by Bulbasaur, but can T-Wave it so problem solved.
Brock- Not useful here, at all.
Misty- Thundershock will rip her team apart. Thunderwave helps to slow down Starmie if it is a problem, but it should go down fast.
Lt. Surge- Can resist electric attacks and learns dig, so this battle is relatively easy.
Erika- Pikachu is not a fan of grass, as I've mentioned repeatedly with the rival. But you can by a thunderstone at the Dept. store, and you still have powerful neutral moves, so it can be done.
Koga- Dig won't work on Weezing or Koffing, but these two have pitiful S.Defenses, so STAB Thunderbolt will hurt it, is very useful. Dig can hurt Muk, but Muk's pretty bulky, so a T-Wave can help. Strength will also work, but if you choose Strength over Dig, do it after this battle.
Sabrina- With Brick Break, Thunderwave, and good special bulk, Mr. Mime will be at a large disadvantage against you. T-Wave can slow down Alakazam and Strength or Dig will both hurt it (strength is better here).
Blaine- If you have Dig, then feel free to go for it after T-Waving. TBolt is neutral to him and fire is neutral to you, so no big deal here.
Giovanni- Just do whatever you did against him the last few times, and it should work out without Raichu.
Lorelei- This is literally the place where Raichu shines brightest. Everything here is weak to TBolt! The only exception is Jynx who can Lovely Kiss you, so beware that, but everything else is laughably easy
Bruno- Just better not to get involved.
Agatha- TWave can slow down her pesky Gengars, TBolt ignores Arbok's intimidate, and Golbat is flying, so there is use here.
Lance- TWave can cripple Dragonite to let your Ice attacker wreck him (if you brought one). TBolt oncwe again wrecks Gyarados. Aerodactyl is tricky though. If your underleveled, then he will outspeed you and Hyper Beam will crush you, so try to use something bulkier instead, or make it Hyperbeam ko something else and TWave it to stop his rampage.
Rival Champ- Pidgeot? Gone! Blastoise/Gyarados? Easy! Alakazam? TWave, physical attack, and laughter at the following ko. Charizard? What a joke! If you chose Bulbasaur, then he has three guys weak to electric type attacks, and one of which with a quadruple weakness. Too easy, assuming you don't screw up against one of his other guys.
Additional Comments- Rare early in the game, and only common late in the game keep it out of top tier. Despite this, its ability to provide coverage against almost every boss except Brock and Giovanni keep it in high tier. Pairs well with all three starters. Provides perfect coverage with a flying and water type on your team.

Have you actually played with Pikachu before, or are you just guessing?

Pikachu runs into a lot of problems, and here's why. You get it early on, but it's practically useless against Brock (unless you just want it to growl Onix or Geodude 6 times and then die). This means that it's useless against the first Gym. You then run into a whole bunch of trainers that use Ground and Grass types, so you have to grind in the wild for Pikachu to keep up. You may have a type advantage against Misty, but you don't resist her Bubblebeam which wrecks you. Sure, you may have Thunderbolt at this point, but that takes grinding against low-level wild Pokemon and that's really inefficient. You can't really grind against the higher ones because they all get type advantages. Further on it gets worse, as both Surge and Erika really do serious damage to Pikachu. And guess what? you run into more Grass and Ground trainers along the way. He doesn't do too badly against Koga, assuming he is appropriately leveled, which is unlikely. But that's where his usefulness ends, because you can surf to the Power Plant to get either a level 40+ Electrode, or a level 50 Zapdos, both who are much more useful. In addition, Pokemon like Jolteon and Magnemite who are much more useful and are also available at much more reasonable levels.

Another thing I'd like to point out is that Gary's Alakazam has Synchronize, meaning Raichu will become paralyzed in return. Even assuming he only had Inner Focus, you would still have to eat a Psychic coming off a base 125 Special Attack just to do the move. Raichu is much slower and has a paltry special defense stat. Agatha also poses some serious problems as Haunter and Gengar are quick as anything and will status you to hell and back before you can move.

Pikachu also comes into a lot of problems due to the way it evolves. It must either wait to level 41 to evolve to get it's best move in Thunder, or evolve early with a poor moveset and always have a shallow movepool, even with TM support. Pikachu also lacks decent availability, as it is a rare find in Viridian Forrest, comes at a paltry level 3 and has a difficult time finding it's stride. Pikachu is definitely low tier, it's outclassed, it's inefficient and while it can be useful at times, it just doesn't seem worth the effort in the long run.