Look, I'm not expert and have no training, but I've noticed that a rather large amount of people online - mostly women - seem to self-diagnose things that will give them what they think is victimhood, but don't seem to diagnose with things viewed generally negatively:
Meaning, you don't see people claiming (admitting) they are afflicted with dark triad traits, for instance. Very interesting.....no, it's the things that are currently considered more fashionable to have: anxiety, OCD, being on the spectrum, etc...
I'd say the people that most need to get therapy are not getting properly dealt with, based on many of my IRL interactions. Some of them are IN therapy or what have you, but it seems they are only there to have their dark triad traits ignored/validated and told they are "victims" of something else. This seems to be causing a wake of damage around them, by the way, because if anything they seem to becoming less well-adapted adults, and more like coddled children with a victim complex to boot.
I think the people with dark triad traits are just flying under the radar as far as having it managed. I bet most people around them if they are honest with themselves, fully realize the issue(s) though.