One thing that never really gets said but everyone knows is true is that one of the reasons transphobes are so focused on preventing trans teens from stopping their bodies' natural puberties is that it scares them if they can't immediate "tell" if a person is trans.

They push to delay transition because it results in trans people looking more "visibly trans," which is what the transphobes want.

They see someone like Kim Petras, someone they'd have no clue was trans if they weren't told, and they get really weird. They want to be able to "mark" us as trans, so they push to make it harder and harder to transition, pushing into the 20s to ensure that we're visibly trans enough for them.
It's why places like NYT will be like, "omg, this person who detransitioned after going on testosterone for a year has a raspier voice than most women now and she has a bit of facial hair! Omg!" Not realizing/caring that forcing trans girls, for instance, to go through a testosterone-driven puberty DOES THE SAME THING. Equally bad, yet they don't see this as a cost.

It's why the theme of "omg, you hooked up with a duuuuuuuuuuddddeeeee?!?!" stuff in movies (The Crying Game, Ace Ventura, etc.) was so popular for so long: it reflects a real anxiety about being "tricked."

And so certain portions of society take it upon themselves to make sure trans people are as visibly trans as possible: they feel entitled to know if someone is trans.

It's all based on really gross transphobic tropes.

A lot of people genuinely seem to think they have some sort of right to know if their coworkers or acquaintances are trans. That's absurd. They don't. It's a wild invasion of privacy.

So they push for policies that make it easier to clock us. It's a big old sexist attack.

Arkansas lawmaker, at a hearing, asks transgender woman if she has a penis

An Arkansas lawmaker shocked onlookers this week when he asked a transgender health care professional about her genitals at a hearing on a bill that would prohibit gender-affirming care for minors.

NBC News