>>30932772Literally just how they make (You) feel.
Objectively, an iconic design paired with a fitting personality and good voice (uwu can rot in jigoku) all make for a good vtuber. Also, producing content people wanna watch. Especially the interactive type. The most important part is that they actually like their fans and what they do.
Then there's the subjective aspect, which is having a niche. This expands a vtuber's market beyond generic variety streamer, and gives them individuality in a sea of sameness.
Finally, don't be a woman (in the literal, biological sense) unless the bulk of your content is higher spec and prerecorded (ie song covers), or you plan on being a vile succubus who preys on simps to milk them dry before kicking them to the curb and pissing off to mootxico with their money (like 99% of female vtubers). For men, actively ward off fujos/shippers and tardwrangle your fans appropriately to filter them out, otherwise they'll drive both bros and possibly even yumes away with their obnoxious attitudes, and you'll become forever pigeonholed as shipping bait.
The big money's obviously still in grifting your fans. But since everyone already knows that, I figure I'd throw out some food for thought. Also, this is why antis exist, because the path to maximum profitability lies through being an unscrupulous psychopath.