I don't want to offend anyone by the term "generic", but by that term I mean the typical Youtubers who generate the same repetitive content over and over and over and over and over again and it's usually content that is made with little effort and often with filler, such as unnecessary jokes. For obvious reasons I won't even mention specific names.
I for example use Youtube exclusively as a learning platform, I can't say I'm a "fan" of any Youtuber because I'm not really there to watch the weekly/daily video of a content creator, I just jump in and if I want to learn about something I just watch it and that's it, I don't get distracted watching anything else.
I hope no one feels offended because it's not my intention but it really makes me curious how some Youtubers can earn thousands of dollars in donations in streamings where they just play a video game, and when someone donates they don't even pay attention to it, I don't even think they need the money.
A lot of people watch YouTube in the same way your grandparents had the TV on seemingly all day. It makes for a good something when you aren't looking for anything in particular. And for that market, the most popular content is simply going to be whatever casts the widest net and thus rakes in the most people. Like sure, there's a dedicated fan base that just absolutely loves watching one let's player break down because another guessed "the Metropolitan mutant of ark" in wheel of fortune for the Xbox, but most people don't find that content relatable. But generic content? By it's own nature, everyone is going to have whatever entry-level acculturation is necessary to understand the enjoyment of it, and thus, a non-discerning audience eats it up.