A good avatar (both the visual and the rigging/tracking) make about 25% of the success of a Vtuber. Then another 25% on how good your social presence is (and how good your PR campaign was to introduce yourself and to keep being relevant). And then the other 50% is all about the streamer.
You can have a top tier effort put into the avatar and the PR for your debut and be thrown into the trashbin if you're a shit streamer (see : Artemis) , but a trash avatar and social media presence will condamn you to be a nobody even if you're a great streamer because people won't even bother.
This also mean that you can be a mediocre streamer and get away on some really good avatar and/or tech that you market well (see : CodeMiko), but in the long run the streamer portion take more and more importance to have a core audience that'll be your bread and butter for revenue.
What happened in 2020 tho is that before that, being a no cam streamer was only a disvantage, nowadays it's expected to be either a Vtuber or a classic streamer. So you could make the argument that the money poured into Vtubing avatar is wasted, but realistically it's the cost of entrry if you don't want to use your IRL face.