So long as other commitments are met, our children can be on screens as much as they want
We also went down that route, as long as homework was done to a high standard and grades and effort reflected that on their school reports, came off when we asked, helped to make dinner, set the table etc, did their chores, came out with us when we said, watched TV shows and films with us and all done willingly they can game, game, game.
Your son comes on walks etc what more do you want from him? Both my sons research the game they are playing, they also watch YouTube to learn about anything from History and Science to how to play guitar. My eldest is 18, youngest is 15, both boys. They are excelling academically, socially and are both lovely people. They game with their friends, even play Uno together. They also both read before bed.
I never understand why it is okay to binge watch a tv show but somehow screen time spent gaming gets a bad rep. Minecraft I do consider to be educational, other games need strategy and planning. Both Dh and I gamed when we met.
What else do you want him to do? Is he happy gaming? Is that where his passion lies? Why is it a bad thing?