I think this game has a bad design. There are no mendatory trainers to beat, so people doesn’t fight them at all. But the trainer were always a indication of the difficulty in the region. But this game is designed with the intention to go to the open world and catch a lot pokemon, which is boring for me. My recommendation to level would be to finish some raids, the exp is decent on them
I don’t like it as well and don’t apologise it with the comparison of a roll model of open world games.