Physical activity and exercise is a good point and I think it's safe to say that exercise is a good, or at worst, a neutral pastime for kids. Probably good, as it would be for adults as well.
What about getting them involved in a physical hobby like a sport, and not restricting screen time? Would that be more beneficial for the kid?
As a dad also in Finland who has a child around the same age... I think I struggle with this wrt my son because I am honestly ambivalent. There is part of me that feels as you do. "Why not? He's active, popular, does sports, spends time with friends, is doing well in school, even has a girlfriend." On the other hand, I know that he would happily give that all up to play Zelda endlessly. When he's not on the screen at home he is restless and bored, which is a conundrum.
What about getting them involved in a physical hobby like a sport, and not restricting screen time? Would that be more beneficial for the kid?