Given that the internet is about the only place that the biological realities of life don't matter

Transhumanism... Or we could even say the Internet is about the only place that reality does not matter. Case-in-point Zuckerberg's "metaverse." If one seeks to make an "alternate/virtual" reality, well, it's really quite there in the words, no?

the internet is the only place where trans women can get validation

The internet is the number one place for crafting any sort of persona, trans or not, irrespective of how that person actually is. They could be, wise, or likeable, or funny, etc. This isn't any different on mainstream social media. Perfectly heterosexual people are equally wrapped up in the internet's siren song, which is: to be anyone you want to be. See the trouble with that? There's some complicity with regards to trans there as well; I admonish everyone on that, because it derives from the mainstream.

So no matter where you go online there's going to be a much higher persistence of trans people than in real life

There are a few spots outside a trans convention where you can find an abundance of them. In my limited personal experience, it's in places dedicated to erotic phenomena. Sex shops, fetish clubs, BDSM "munches." etc. This mostly pertains to the common MTF type. FTMs, in my experience, are lacking from public or quasi-public places. Curious... worried... where are they? But I never get the intuitive sense that the MTF in these scenarios are comfortable. It strikes me that they're walking on eggshells, yet prepared to lash-out. They're seething, internally, but, it's not the Internet, and real social rules apply. Maybe it's just the exaggerated high-heels they're wearing without much experience, but no, I think... they're tying to have peace from without, as opposed to within. It's exhibitionist, but yet a cry for acceptance. I don't think they're getting it, never mind the more lax attitudes about well, everything in these sorts of places.

Lesbians... because they are only interested in females

Which invalidates the transsexuals' wish that they are female. Because lesbians are not into them, thus, not female. Lesbians don't like men. Lesbians don't like MTF trans, thus, not women.

Male-to-female transsexuals are generally not inviting the validation of men, because men are often not the object of desire (with the exception of behavioral homosexuality--because it is "women" who have sex with men.) Combine this with the co-option of LGB...TQ+ and the circuitous assumption that it's always been that way, as one, big happy family, it's understood as a betrayal--one of the worst offenses--that they are on high alert for.

Or, simply put, they seek sexual validation, not societal validation per say, but sexual validation. They're not getting it, and it's causing a huge ruckus.

Finally, I'll add, I don't think we're giving enough credence to sexual phenomena. You might not like them, but they are here, present, and they are compelling. Case in point?