I assume it is for gameplay reasons, specifically to add a bit of extra tension from possible failure. It could also be to make grinding slightly less tedious, for there wouldn't be a prompt asking the player about using a pokéball each time one takes out the pokémon (which is otherwise deleted upon fainting.)
It might also be due to programming issues, but this is all just speculation.
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KoimanZX
Sep 25, 2022 at 08:48PM EDT in reply to
Lord DIO
Sep 25, 2022 at 07:02PM EDT