One would think that the theme park closures due to Covid this year would have highlighted that fact for them. Vlogging in this industry just fills a temporary need that comes and goes as the winds change.
Some vloggers have survived well though the closures, they were working on improving their approach and tech. Some vloggers are also so new that they could only grow. Dev kind of falls into the latter, from what I recall he had essentially closed down his channel, lost his subscriber base and then opened it back up slowly seeing growth, then suddenly saw exponential growth as the top dog decided to sit on his ass at home waiving his baby in the camera. His sudden surge caught the eye of Disney marketing (or he probably pointed it out to them). That does not make him a good vlogger, it makes him undependable as a vlogger right alongside that jackass Spokesmayne who HAS talent but keeps blowing it over and over again with his drama.