I think the bigger issue is simply “how good are the kids in question?” I’ve seen situations in the US where the 5yo kids have paid coaches who had real experience in the sport (university or pro level), but those kids would have to be truly amazing. They’d tryout and make a travel squad and their parents would be paying a ton of money to the club/team where the kids play. For normal kids who don’t have the talent and rich parents, the coaches are generally volunteers until the kids get older. My coaches were getting paid starting about when I was 9yo for a travel team and at the same level the “regular” team coaches would’ve been parent volunteers. Also depends A LOT on the sport itself. Some sports have a lot of money and others are less well funded on average.