>>54626940EVs, IVs, and natures.
It'd be fine if it were all optional for the competitive players. But my autistic brain hates starting a game and being told I have to spend hours resting for the right nature and killing hundreds of the same pokemon to play optimally. And even IF I play along and do it, my pokemon could still be shit because of an invisible number that I can't manipulate at all in most games. A feature that literally only exists to make some pokemon weaker than others of the same species.
Granted I'm aware brute force, potions and overleveling can somewhat combat this. But A, I don't like using items in battle. B, I don't enjoy grinding until nothing is a challenge anymore. And C, that doesn't even work consistently either! And it sucks for a franchise built on the idea that any mon can be champion material if you try hard enough.
>Sorry bud, but you have no attack IV's and I didn't spend 3 hours fighting Machops! I can't win with you! 