How can you support trans people transitioning given they may regret it? It's such a dangerous thing to do, especially since it isn't reversible.
If we were to take your stance that only procedures which are reversible and which have a 0% rate of regret can be performed, and apply it to other medical procedures, virtually no surgeries would ever be allowed.
Transitioning is a process and a person may stop anywhere along the way and not move forward, many never go as far as getting surgery.
For most people it begins by changing their name and the clothes they wear. For any transitioning beyond this, mental health professionals are involved.
The standards of care are that the individual be in therapy before they're allowed access to hormone treatments. In order to qualify for surgery, they need to do hormone therapy for a year and get approval from a mental-health professional. Then they can find a surgeon, do the pre-surgical appointments, and finally get the surgery. It may be that the individual's insurance won't cover the cost of the surgery, so the individual also needs time to raise the necessary funds.
This is not a quick or easy process, usually it takes years before the person gets to the point of having surgery. I don't know any other medical treatment that requires so much documentation and therapy before being able to proceed. This has led to the following joke:
How many trans people does it take to change a light bulb? Just one, but they need 3 specialists to sign off that the room is, in fact, dark, before they can make the change.
Some people do de-transition, I believe the statistics are about 8%. For about 2/3 of this group, the detransition is temporary, and usually it's due to external pressures, like difficulty finding a job, pressure from a family member, harassment, and so on.
Because it's such a gradual path supported by psychological counseling, the regret rate is extremely low. The studies I've seen put the regret rate between 1% & 3%. When regret does occur, the reasons vary and it could be medical complications, it could be dissatisfaction with the physical results, or even saying they were wrong about their gender identity. The regret rate is far lower than other things we allow people to do all the time without getting mental health professionals involved, like getting LASIK eye surgery, knee replacement, getting a tattoo, surgery for prostate cancer, or having a baby (8%~17% of parents say they regret having a child).
The positive benefit of transitioning (whether it's social, whether it's with hormones, or even with surgery) make such an improvement in the trans person's life, that to outlaw it would be to cause harm to many people. Safeguards are in place to minimize the number of people who may later regret transitioning, and more data & studies are needed so that we can do better.
