I don't think that's true. There's a lot of video creators making money through a bunch of platforms. A lot of people that seem successful in this space post single images + changes with the occasional live2d loop. Quantifying success is also difficult. For most of the people, it's likely just a side hustle. Every scene though, is a lot of extra work. How someone got captured is likely more time consuming than the H animation since there's a lot of moving parts. Having the 2 main subjects in similar positions throughout the scene greatly reduces complexity and therefore time to animate.