‘An awful lot of the people claiming to be “systems” are trans &/or non-binary. Or claim at least one of their alters is.’
But they are not all claiming to have DID or any other mental illness. From the links provided on here to Twitter hashtags and Reddit, it’s a bunch of people who believe they have summoned Tulpas or have personality symptoms or sub personalities or schemas, none of which are really anything to do with DID.
Multiple personality stuff is popular at the moment. Jordan Peterson is popular and he promotes Jungian sub personalities. IFS is growing. Guardian Angels are a popular idea, as are tulpas.
I may be biased here because I use IFS myself. But the stuff linked to on here shows links to people talking about having plural personalities, sometimes in quite an irritating manner, but they are not all claiming to have DID, which is a serious and controversial diagnosis because of the level of dissociation.
I don’t see a rise in people claiming to have dissociative experiences. If anything dissociation is the opposite of online life where people seem to be engaging in some kind of hyper reality, not dissociating from it.