This isn't purely new, either. I'm perhaps dating myself a bit but I recall that over the years I have seen a few actors have this weird vibe where they're never "human", they always "on" and seem like their actor-thing has totally subsumed their humanity.
David Cassidy and Shirley McClain come to mind for me on this.
I realize I'm probably in the minority for this, but for me when people create a "persona" for their media, it turns me away. I prefer watching people who are more genuine, whose content is less entertainment and more just themselves, even if that isn't what the internet seems to be looking for.
I think it's even more complex than that. There's only one human I can understand pretty thoroughly, inside and out, and that's me -- and even then, there are a lot of limitations!
We cannot know all the thoughts and experiences of another human being. Even when that person is 100% genuine, there will be aspects to that person that will surprise you!
And that doesn't even get into the weeds of autistics, ADHDers, and intelligent people (I happen to be all three) -- who learn from an early age they have to pretend to be something they aren't, otherwise they'll face intense bullying and ostracision. And even then, there's going to be something "off" about them ....
David Cassidy and Shirley McClain come to mind for me on this.