We always had my son play up. When he was 10u he was playing 12u. When he was 14u he was playing 16u. On top of that, puberty hit very late. So, he was always the smallest on the field.
People thought we were nuts and punishing him. But, he was always able to compete and hang in there with the older kids.
Guess what? At 15, as a HS freshman, he made Varsity, was a starter, and led the team in HR. Playing with and against older kids never bothered him in HS because he's always been doing it.
Different strokes for different folks, I guess? I get that it must be fun to be the man among boys and dominate. And you will get to college older and colleges don't want teenagers. These are pretty much facts.
I won't fault anyone for doing it.
Me? I just always was impressed by the younger player who could compete with the older players. I think that's not odd...people are fascinated with Juan Soto and the like when they star in the majors so young.