I don't mind MrBeast, but what I really hate is how every other YouTuber has decided to copy his "screaming face" thumbnail strategy. My YouTube home page is full of screaming faces and bright text with some clickbait title. Even middle-age woodworkers (the polar-opposite audience to MrBeast) fall prey to this strategy, and I've started to unsubscribe from channels that insist on doing this.
Absolutely sets off the uncanny valley alarms in my dumb lizard brain. And then like you mention, people have latched onto the aesthetic because it works, so it's all over the place. But it's just instant unease and feeling of "Absolutely not." that I don't get from something like e.g. this person does not exist. Very anti-asmr like.