"Livestreaming" is not a career, and one of the main benefits of the anonymous nature of vtubing is that it makes it that much easier to stop doing it. Grinding out hours of footage everyday might get you numbers but it's a model that's fundamentally unsustainable -- only NEETs can do it, and only NEETs can keep up with it. The fact that most full-time vtubers will only last a few years is a simple reality propped up by the fact that for most viewers, vtubing will only be a hobby for a similar period also.