>>24075053>Honestly the border between "vtubing" and just "anime" at the start was pretty slimBefore VTubers, there already existed anime series that didn't have an actual script and were just improvised by the VAs during recording. That's very close, but I'd say the main difference between that and VTubers is in what's the main attraction.
In anime, you could switch out a VA inbetween seasons, and as long as the new VA does a good job with the character, people would probably still keep watching the show. In the case of a VTuber, the viewers are there for the VA themselves, and will normally follow them even if they redebut under a new identity. You absolutely cannot recast an existing character with a new VA and expect that to go well. Some companies (Unlimited, Activ8) learned that the hard way.
(And on that note, the one in the last video you linked is actually Love-chan, not the "true" AI.)