>>55648766it depends on a lot of factors
firstly: how easily can the pokemon be obtained? platinum's size of 210 is healthy on paper, version exclusives notwithstanding, but a lot of the mons require trading to fully evolve. for someone playing singleplayer, this is a problem. same with johto. 251 pokemon feels like a lot, but between trade evos, stone evos, swarms, and postgame exclusives, it's surprisingly slim pickings.
secondly: how many new pokemon are there? it's nice having your old favorites in a new region, but when people buy a new pokemon game they're going to be looking for new pokemon to use. BW has a dex of 152 new mons, not counting mythicals. this would seem small, except all of the pokemon are brand new so there's plenty of replay value alone in wanting to try everything out. BW2 is in the opposite position. it has a dex of 300 but nothing is new. balancing gen 5 mons with older mons isn't an issue because everything has had their chance to shine in a previous game.
contrast both of these with XY who has an even larger dex of 450 but only 69 new mons, again not counting mythicals. the large dex size is a detriment here, the old completely overshadows the new. fuck's sake the aces of both the evil team leader and champion are just megas of older pokemon.
thirdly: how good are the mons? johto and hoenn both have a lot of pokemon that just suck complete dick and nobody in their right mind would use, they don't even count as options when teambuilding.
attached is a tier list of how i think each game's dex stacks up. note that this doesn't correspond to my opinion of each game as a whole, just in this specific department. and i'm excluding the switch gens because i never played them.
