My bag is full

I always have tools equipped, but since I don't have anything worth discarding, I just throw away balls or unused berries, I guess...

As the commenter above said, it's best to prioritize and discard items. Similarly, for Pokémon, it seems like a good idea to set priorities for battle-ready, high-IV, shiny, or background Pokémon, and then sort out the ones you want to keep.

I found it too bothersome.

I discard the fruit.