Hikikomori are also well "networked" online and play the game of who is authentic and who is fake. Perhaps it is as popular as it is because it has become an identity.
I have read a fan translation + to-fiction conversion of a japanese manga about a hikki who died saving other people, ended up in a fantasy world and became successful. The sub-culture is definitely going strong and international.
Mushoku Tensei (Unemployment reincarnation)
And that identity would be otaku?
Welcome to the N.H.K. is an anime that explores Hikikomori.