>>43100398The lore explains it, specially BW1
The pokemon aren't slaves, they cooperate with people.
I'll post some stuff, because I am lazy and you obviously don't know your lore, and should be hanged by your balls (if they are even balls, you probably have some fucking peanuts there or even smaller).
Long ago, when Sinnoh had just been made, Pokémon and humans led separate lives.
That is not to say they did not help each other. No, indeed they did.
They supplied each other with goods, and supported each other.
A Pokémon proposed to the others to always be ready to help humans.
It asked that Pokémon be ready to appear before humans always.
Thus, to this day, Pokémon appear to us if we venture into tall grass.
sinnoh myths
And in BW1, when you arrive for the first time to the next city, after ghetsis shitposts his shitty talk, the npcs there clearly meention how pokemon are free to leave their balls whenever they want.
I know you might pretend anime isn't canon because of some stupid shit there, but since this was in the game already, we have seen wobuffet and other pokemon leave their ball by their own will. Chikorita did this as well.
