Autogynephilia existed long before the internet too. It just used to be treated before. And most guys kept that shit in the closet. There used to be a trope in drama and comedy about a woman walking in on her husband wearing her underwear.

Some of it may be linked to pornographically-stimulated fetishes. You're being disingenuous when you say autogynephilia or the trans-tend is not related to pornography at all. Porn is older than history itself, but society has really only been immersed in it since smartphones put normies on the Internet and put the world history's entire catalog of porn in their pocket. We can get off to any kink we want at a moments notice, and most children have no limitations preventing them from doing the same. If you are in your 20s you may not realize that teens used to go out of our way to see tits. You had to secretly watch late night cable-tv or steal your dad's Playboy. Sometimes a kid would take a dirty magazine to school and they'd get in serious trouble for it. Even in the early Web days - when I'm sure every male teen typed in "sex.com" at least once - it was still something you actively sought out unless you were being groomed. Now with such easy access we have created a hypersexualization of youth with strange results, where the remaining non-sexualized ones think there must be something wrong with them.

I wouldn't say porn is solely to blame. It is a complex societal issue, where a lot of things (yes, including rampant misandry) have converged to cause today's problems. It's just one factor.