i was looking at gen 2 sets on Smogon and saw that Espeon's set was centered around "growth." Which confused me because I didn't think it got the move in the game. And then I read about how it was an event move. And idk. it's hypocritical because the entire advantage of Showdown is that it's wish fulfillment, you can make your team exactly how you want down to a t. but it feels stupid that a Pokemon's entire point in the metagame revolves around a move that 99 percent of players didn't have access to when the games were popular.
Speaking as a guy that once tried to make an entire holiday centered around this Pokémon
apparently the actual Espeon Day is August 21st but that’s beside the point, I just wish this thing was dealt a better hand in general. It’s actually pretty solid in Johto, what with being an alternative to Alakazam for players who can’t trade and having decent stats and Psychic actually not being that bad of a type for those games (even Karen runs two Poison-Types and it would have been three if Umbreon didn’t get reworked), but so much of this thing’s competitive history just isn’t that unique to it or even all that useful.
At first glance, Espeon seems like it should be a solid, if unspectacular Pokemon in most generations. Gen 4 was a bit rough for it and some other Psychic-Types in general, but Magic Bounce was a fun addition in Gen 5, Calm Mind means it didn’t get as hurt by the removal of Growth as many of the other Eeveelutions, and I don’t know if this is still true but for a while it was actually better in the current generation than it was in Sword & Shield if we’re going off of our tiering system. Unfortunately, Espeon struggles with a lot of things other Psychic-Types do, and a lot of its strongest appeal comes from strategies that have either been banned (Baton Pass) in most generations or only see inconsistent matchup-dependent success (Screens, Wish, etc.). Even if Alakazam didn’t give Espeon strict competition, base 130 Special Attack and base 110 Speed just isn’t what it used to be, and historically it hasn’t had much in the way of type coverage, any defensive utility (against attacks, specifically, Magic Bounce helps for status moves) or any sort of preferential treatment besides maybe Morning Sun in Gen 2. As an Eeveelution, its matchups with and against the others aren’t strong either. Not only does Espeon tend to not have very strong synergy with some of them, but it’s actually the only one to not having any winning matchups against any other Eeveelution type-wise.
I fear that even in the best case scenario where this thing receives Glitzy Glow (Eevee’s Psychic-Type move from Let’s Go), generational power creep has gone way too far and that Espeon’s only going to be harder to fit into a wider variety of teams. I actually thing it’s somewhat underrated in Doubles, with Magic Bounce helping against certain utility moves and Dual Screens always being fun to build with, but going back to your original point of your post, I agree that it’s probably not good game design for a Pokémon’s entire niche to be based off of specific generational factors like this (provided Growth specifically was an event move, but still).