I have no idea why this option is not in Scarlet and Violet yet, though I'm assuming it will eventually added one day.
We'll get it right after they bring back the exp. share toggle.
God forbid anyone deviate from Gamefreak's linear vision for playing their games. Why bother making it open world?
Even more awkward is that those online competitive battles are always set to Set, even in SV!
They've always been stubborn. For example: poison and leech seed or DoT(wrap and fire spin etc.) play styles are never going to get buffed.
Well the styles they had in legends arceus were around because technically because the current battle style was not set up in that time hence why their is no gyms
I feel really bad for the people who like doing challenges. They have to eternally play the game on easy mode and know what their opponent will send out next. And speedrunners will lose so much time spamming B.