Regional burns are espoused to celebrate "radical self-expression" , and unlike the Big Burn, their smaller size seems to promote authenticity to a greater degree. But even there, people are doing bits or acting out a persona or even just socially experimenting.
Authenticity itself is nebulous. But even taking that into account, there are definitely more harmful and less harmful facades. We pay actors and performers to be inauthentic. But we consider influencer "fake".
Point is, I don't think "authenticity" is the main metric we actually care about. Inauthenticity can be lots of fun for all parties. It's the motivations of the act. It's the second-order authenticity. An actor is authentic in their inauthenticity: there's no hiding that they are putting on an act. But we dislike influencers and the like because while they are (often obviously) inauthentic, they try to hide that fact under a facade trying to make it seem like it's their "real expression".
As a counterpoint, take a youtuber I really enjoy, Ryan McBeth. He does OSINT mostly military-themed current events vids and blogs. I'm sure the Ryan in front of the camera is different than the Ryan I'd meet at the bar: more polished, calculated in choice of words, presenting self in the best light, because that's what we all do in the limelight. But he totally lampshades his sponsored bits: "let me take a few moments to pay the bills". That's the second-order authenticity. Doing a paid sponsor bit is ipso facto inauthentic - it's not something you'd do without the influence of money. But lampshading it tips his hand and humanizes him. Or does it? <vsauce theme> Maybe he's saying that because his shtick is "down to earth authentic guy" and that's what that character would say? (I doubt it, but it's a fun hypothetical).
Famously, "All the world’s a stage, And all the men and women merely players" - Shakespeare