>>38657729>You get a decent mon selection even before the first gym and there's plenty more to find with each new route.The only mons obtainable before Brock that remain usable at are Pidgeot (Fearow as your alternative), and the Nidos. After Brock, it's slim picking. Zubat was not a good choice due to no Crobat yet and it couldn't even learn fly and its base moveset sucking dick. If you have Bulbasaur you don't need Bellsprout (who doesn't learn a good STAB until level 33 so still sucks balls), and if you're playing Blue/LG you're shit out of luck because Oddish is even worse. Between Pewter City and Celedon, the only bearable Pokemon to use are those that effortlessly smashed the game (Kadabra, Gyarados, Dugtrio).
Magnemite sounds good until you realize its only offensive options are Tackle, Swift, and Thunder Shock (Spark and Zap Cannon were added to its move pool in FRLG). Voltorb sounds cool until you realize that Voltorb is shit and doesn't learn a STAB by level up in gen 1 and gets Spark in FRLG. Machoke sounds good until you realize it best moves are Karate Chop and Low Kick, both having a BP of 50. Graveler sounds good until you remember that Dugtrio exists. Growlithe sounds good until you remember you're stuck with Ember for STAB until level 50 (learns it at level 49 and gets Flare Wheel at 31 in FRLG and is locked to FR).
These Pokemon are good on paper until you remember how Godawful their level up moves are and how much they want you to grind for them ie. Scyther learning only Scratch and Slash in RB and getting Wing Attack in Yellow, a 35 BP move, and learns it at level 50. Gen 3 much better with the only Bug STAB move it learns on level up being Fury Cutter at level 46.
I implore anyone who says that RBY and FRLG has a good Pokemon selection to play through the main game with to go back and actually try to use a team of mons they have never used in their previous playthroughs. Most of them are really worthless.