>>34783443>Natures/IVs/DVs don't matter in the storySure they do. It can be annoying when a 2HKO becomes a 3HKO, or your defences are so shit you can't take even a neutral hit.
It's not that GSC is immune of this, but it is not to the same level.
And I mean, I like training Pokemon in battles. That's what these games are, it makes no sense, but you enjoy what you do and that's it. In RBYGSC, you can do whatever the fuck you want with respect to battles. In Gen 3 on, you can't.
For example, if I use an Espeon to knock out a Machoke, fuckin A, since it's a Psychic type with a high Sp Atk and Machoke is weak to it and has low Sp Def. No problem, right?
Depends what game you're playing. In GSC, no problem. You're gonna get the equivalent of Attack EVs, but that's alright, even if you don't plan on ever using Espeon's physical stats, because maxing out Espeon's attack doesn't block you from being able to max out any other stat. You can max out every single one of Espeon's stat.
RSE gives you +2 Atk EVs. Now we're in trouble, because +2 Atk EVs is 2 less EVs you can spend on Espeon's Sp Atk, Speed, etc.
And natures? Yeah, you can go with a nature to *boost* Espeon's Sp Atk or Speed by 10%, but you have to pick a stat to *reduce* by 10%. It gets real ugly real fast when you think 'ah, fuck it, I might as well run Shadow Ball Espeon anyways since I've boosted its Attack so much by knocking out a bunch of Machokes for easy EXP', but you went with a nature hindering its attack. Now you have a poorly optimised Pokemon with lousy EV investment, a weird nature, and, fuck, it doesn't have its Hidden Ability.
A Pokemon you catch in-game in GSC is usable, is fun to level up and max its stats out. Very few Pokémon aren't unusable right out of the gate, and you don't need to go through hell to train them.
A Pokemon you catch in RS-on is shit, not fun to catch the right one, and not fun to train up. Doing whatever you want will end up with the game de facto penalising you.