Then how do you account for the fact that thousands of adults in countries such as Sweden, Germany and Japan have sued and obtained compensation for being required to give up their capacity to reproduce as part of their own gender transitions that they underwent as adults?

Isn't that because those countries used to require sterilization to transition legally? Yeah that's awful, and I wouldn't even say they had free choice in that. But that's different than freely choosing transition knowing it will lead to loss of fertility. They made that choice, it is not a doctor's job to predict with certainty where your mind will be in the far future. It's the same logic that doctors use to misogynistically deny tubal ligation or hysterectomies to young women. No other condition is treated this way as far as I know, nowhere else do we withhold treatment just because of the mere possibility of regret.

How do you respond to the fact that many people who have no interest in having children ever when they are in their teens and 20s find that in their 30s they feel totally differently?

People can change their mind, so what? That can literally happen with anything, they should take responsibility for their choices. If they chose not to bank sperm years ago when they had the option then that's no one's fault but their own. All dysphoric people deserve support in the present, whether they've transitioned or detransitioned or anything in between. But acting like woe is you because you didn't foresee the potential consequences of your actions doesn't entitle you to control others' choices.

Yeah, it's possible that in 10 years I'll regret getting an orchiectomy or transitioning. I doubt it, because the idea of having biological kids makes me want to vomit, but yeah it's at least vaguely possible. But if that happens I'll handle it then, and if I have regret it won't be any different than like, deciding not to go to grad school, or whether or not to stay together with a partner. All decisions that greatly affect someone's life trajectory and experience.

I don't see you rushing to try and prevent people from making literally any other kind of choice they might regret later, so you shouldn't for people transitioning either.

Also, even though I think I'll be too old by the time it's ready, young trans women may be able to receive a womb transplant in the future which could also eliminate the need to bank sperm at all