I think another aspect of vtubing is that the entertainment industry is so heavily dependent on looks, but with an avatar someone who has actual talents, rather than "talents," can level the playing field. It's also an easier point of access for those who are shy (we know a decent number of the holoJP girls are in this boat, and I suspect Gura is as well to some degree) or who need to live remotely for whatever reason. This expands the field of people who can effectively make a living singing, playing video games for an audience, and generally just being funny and entertaining. What we're seeing is an infusion of real talent into a field that has heretofore been dominated by those who rely on their looks. You can even see this a bit in Pokimane's dabbling in vtubing, which she has said is because she want to use it on days where she isn't all made up for the camera.
Basically, hololive girls are to Alinity what Projekt Melody was to camgirls.