You're mostly comparing legal and financial ramifications to self-identity. I trust a teenager more to tell me who they are than to pay back a car loan.
From the little research I've done, puberty-blockers don't have long-term effects and most kids aren't on them more than a few years. This is widely agreed upon in the medical community. There is non-biased research done on this for decades you can read up on.
Yes, being a teenager is weird and confusing. Even more so, if you feel like you live in the wrong body, I imagine. That's the exact reason puberty blockers are effective, by giving a teen a little more time to figure out their identity, without it being rushed or compounded by the effects of puberty.