For some reason the most pessimistic voices always get boosted the most on social media. (Well, on my corner of Akkoma/Mastodon, that is.)
While, yes, there is a large anti-trans campaign going on in the US, and yes, it's succeeding scarily often, it is failing just as often. The threat isn't from a hateful majority, it's from a minority in power. One way or another I believe it's a losing battle for the bigots. We exist and nothing they can do will change that.
I hope that the rest of the space including the W3C sticking to their guns and opposing Web Environment Integrity prevents this from doing too much damage, but Chrome's monopoly is already at such an extent that many websites only test on Chrome, and a few outright require it. As long as this is implemented in Chrome, and if people who use it get more return from ads as the proposal suggests, some websites will be willing to implement it.
This is definitely seeing more and stronger opposition than the Encrypted Media Extensions proposal, but my fear is that it will go in that direction; if big websites implement it, Mozilla, Vivaldi, and W3C will eventually cave despite their initial opposition.