#like its very much an occham's razor sort of interpretation of the game mechanics

[tiktaaliker]

Honestly i imagine that any attempts to fake a stat boost/lowering would get Arceus's attention and Pokemon God would make it real. Arceus may not always answer the prayers of its creations, or even help that much in day-to-day life, but you better believe that any Pokemon trying to cheat in battle would get its attention Real Fast lmao. (Except if you're volo and you being seven Pokemon to a battle, or if you're a legendary being kidnapped to fight against a small child and their Pokemon. Or if you're rei and you're fighting other Pokemon with Pokemon while pretending to be human.)

I also headcanon that in-universe it's responsible for the changes from generation to generation. Picturing old grandpa/grandma Pokemon going "in MY day there was no 'waiting five turns for the weather to go away'! WEATHER WAS PERMANENT AND YOU COULD ONLY CHANGE IT USING ANOTHER WEATHER EFFECT!! you kids don't know how good you've got it-" and their grandkids going "ok grandpa/grandma, let's get you to bed..." Arceus nerfs Pokemon in-universe just so their powers aren't TOO op lmao.

lol ok arceus being like REALLY into battling fits tho especially with the weird battle gauntlet you can do post-game in legends. Like every once in a while Arceus is like "actually this needs to be rebalanced to make battling more interesting". which ALSO would explain stuff like the difference between frostbite/freezing between legends arceus and the main games along with sleep not actually having a pokemon sleep or status conditions not persisting outside of battle. arceus just hadn't figured out how it wanted everything to work yet. and THAT even accounts for abilities not being present for legends arceus or the first two gens either. arceus just one day thought it would be cool and made it so.

in sort: the pokemon universe is the way it is because the pokemon god is a hardcore gamer