I had one of those inner tubes attached to a vest when I was small, then I wore water wings. I learned to swim very early on, though.
I took private swimming lessons and went to Catholic school, so we didn't learn to swim in gym class or anything, we played dodgeball in a church parking lot for gym lol. But most public schools around here teach swimming as part of gym class in 3rd grade or something, so most kids would eventually learn to swim anyway, life jackets or no life jackets.
From what I understand though, a lot of kids in and around the bible belt are homeschooled. Yet another one of its drawbacks!
I don't think there's any need to ban life jackets in pools. If anything, they should ban kids under 3 or whatever from public pools because they PISS AND SHIT in them and it's gross.