funny to see this come up since i was just thinking about it today after seeing some videos about it in the last week. to put it lightly, i absolutely hate them lol. as you mention- they are completely made up. i mostly hate the use of buzzwords like "robot" "AI" "virtual" etc etc for a thing that is more often than not... none of those things other than being represented by a virtual avatar. it is, at most, a virtual avatar being played by an actor with a written script to go by- all perfectly directed towards trends and going viral, by some corporation jumping on trends. there may be some level of AI written songs perhaps, maybe. regardless, the methods to which they supposedly use AI becomes pointless with the methods of its actual presentation (acted by/voiced by a human, for one). Overall the vagueness of them is annoying to me in this regard, bc it leaves a huge grey spot in the legitimacy anyways, while the companies go off to have solemnly voiced interviews of the characters talking about being ~real~ or ~born~ or whatever.... Like, the vocal synth scene is all about creative freedom, and collaborative art, and nearly all of the content is fanmade. Meanwhile, these virtual "influencers" (not to be a boomer but I think I'm really beginning to really hate this term/concept) are pure corporate artifice that lack any of the community and creativity that actually made Hatsune Miku et al. the icons that they are today.
Just a lil ol' rant from lil ol' me!
some of the stuff i see people say in regards to it like 'bringing together... the virtual world and the real world' are just... it is just nonsense. it doesnt mean anything at all, not really. so many words twisted into meanings and ideas all hyped by companies wanting to make money. in the end its a cash grab with little to no heart, and lies or vague truths to pull interest from people who don't know anything about the prospect of a "virtual artist".