Yes, we should absolutely ban, at the very least, contact football among minors. We have ample evidence of football (and soccer, too, for that matter) student athletes developing full blown CTE by their 20s, and with lifetime risk thousands of times the general population.
100% anecdotal… one of my town’s youth football (American) clubs shut down before COVID due to lack of interest. When my son played ~15 years ago, the club was fielding 2 teams per age group.
And knowing what they know now, I wouldn’t let a child play today.
I do suspect that soccer has whittled down youth American football over time. It's not quite true that no one played youth soccer when I was growing up but certainly nothing organized at scale to today's degree. I have a friend who has been reffing soccer forever. I should ask him as he probably has some insight.
ADDED: I suspect a combination of the negative publicity for football, less equipment for soccer, etc. Even if American football still largely dominates as you get to college and the pros. Some rugby in college but relatively not a lot in the US.
A few years back, I thought there would be more of a push to regulate/limit American, at least contact, football. But didn't happen. Soccer? Good luck.