If you let them destroy their young, still forming bodies many of them will regret it and commit suicide later when they realize they have irrecoverably destroyed their natural sexual function. They are children with a limited capacity to understand the totality of how this will impact the rest of their life. If doctors and schools communicate openly and honestly with parents (which they don’t) the situation can be handled in ways befitting a minor.

Actually, the rate of transition regret is remarkably low, including among those who began transitioning early in life. The most common reason for regret is social stigma.

If you think trans care should be banned because people might regret it, then you need to ban pretty much any permanent medical intervention.