YouTube, like much media, is essentially the art of telling people what they want to hear.
Start by saying stuff, and then amend the message in response to feedback so that the numbers increase. The fact they might end up talking bollocks or stuff they don't believe isn't really important, because the aim is maximising visibility and revenue. Although I suspect it is worse than that because many, in the hunt for fame and income, are liable to end up shifting their beliefs towards the expectations of their audience.
In fact, I think I recall a paper on this for science and medicine social media producers. These guys are not neutral interpreters of truth, they are often profoundly influenced by audience-chasing like everyone else.