Well, that's not quite accurate. (a) there isn't a large increase of trans people, historically speaking, just folks being more open and honest about their status recently, since it's become marginally less punished in a few specific places, than it has been prior, and (b) in recent years, trans men or transmasc folks are the largest group of those new influx, not trans women.
> There are massive amounts of compounds in our environment that are endocrine disrupters or mimic sex hormones like estrogen
If people were getting estrogen in the environment that they didn't want in any amount meaningful enough to effect them, you'd wouldn't expect to see more trans women (trans women, generally speaking, are usually deficient in estrogen), you'd expect to see more dysphoric men. You'd expect to see a sharp increase in cis men presenting with ED and gynecomastia and such. (Which, to be fair, is a thing we're seeing. But so far, appears to be mainly linked to increasing obesity rates)
> Maybe they would even benefit more from hormone treatments in the opposite direction than the "gender affirming" treatments.
This is barbaric if you think about it for more than 5 seconds. So barbaric in fact, that it's been outlawed in many nations -- see https://en.wikipedia.org/wiki/Conversion_therapy for more info