It has worked so far because the videos used to be good and years ago Youtube wasn’t as competitive. From then on, once you amass a decent amount of subscribers it’s fairly easy to ride the wave. It is also worth mentioning that his videos are very obviously focused towards “casual” audiences, most of which won’t even know when he is showing bad data or doing a poor review.

they call nVidia names all the time, and keep bashing its practices.

Sometimes? Maybe. But let’s not pretend like they haven’t been called out by the community multiple times for being “too soft” when Nvidia pullsed some shit, even when other reviewers did complain.