I agree, like you can stow whatever commentary of envy and capitalism, I can tell you the precise reason I don't like MrBeast is the thumbnails.

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.