Most gender affirming care consists of puberty blockers and possibly hormones. Surgeries don't usually occur until after a person has reached adulthood. Until surgeries occur, pretty much all gender affirming care is reversible. However, puberty causes body changes which are mostly NOT reversible and/or very expensive to alter.

There are NO professional medical organizations who support such laws. Such laws are rooted in religious beliefs alone. Those who support such laws may claim they are "protecting children", but the very children they are supposedly trying to protect, feel that they are in fact beign attacked and discriminated against for who they are.

It took decades of research to come to an understanding of "gender dysphoria" related conditions, and there is a long screening process involved before anyone is granted treatments. Sadly, outside the professional community there is little understanding of gender dysphoria or the best way to treat it, and the laws banning gender affirming care are primarily written by laymen who have no understanding, but are mostly motivated by religious base prejudices.

In the end, these laws will mostly end up making society better educated abotu gender dysphoria condition(s). Just like AIDS initially stirred up a lot of hysteria against gays, but in the end people got educated because it was always in the news, and they came to find out they knew a lot more gay people than they thought they knew. I expect a long term result to be similar.

However, in the meantime, a lot of kids will be forced to go through the puberty of a gender they do not identify as, which means their body will makes some changes which are irreversible... as if our society didn't already have enough issues with body image...