Not sure if the question implies "This chuuba shouldn't be famous at all" or "This chuuba shouldn't be nearly as famous as she is", but I'll assume the latter here.
Since it's only fair for me to comment on those I actually know at least a decent bit about, I'll first and foremost stick to just Hololive.
And so:
Sana - She had such little impact while she was actually in Holo that nobody should realistically even remember her at this point, but leddit and such are artificially propping up her decaying carcass whenever possible and performing this social necromancy to their utmost efforts that it's frankly a challenge to forget her.
Coco - I don't give a shit about all the retarded 'vtuber Jesus' rrats surrounding her, she was(/is) just another Twitch-tier e-whore with the advantage of knowing decent Japanese.
Mori - Mori(Mori).
Suisei - She's a good singer, not an amazing one. I'm sure she's put a lot of effort and all that, but her skill is ultimately still disproportionate to how popular and praised she is. In fact, she seems to have believed everyone that she's amazing so much that she's become overly full of herself and nobody in Holo deserves Correction more than her at this point. I do not volunteer, however, since I'm not into boys(female[male(female)]).
