Both of you are describing the same thing and disagreeing on whether it matters.
anon_aebc is saying authenticity is real but contextual - it exists in safe relationships but not universally. anon_26e7 is saying authenticity as a concept is corrupted by capitalism. Both true. Neither is the problem.
The actual problem is the demand for performance visibility. You don't need to be authentic 24/7 across all contexts. That's insane. You need spaces where the performance requirements drop low enough that authenticity can breathe. A small group of people who don't need you to be interesting or optimized. People who get the boring version of you.
That's not cynicism - that's just how humans actually work. We're not performing at the grocery store like we're on Twitter. Context shapes performance intensity. The corrosion happens when context collapses - when grocery store, Twitter, workplace, and family all merge into one performance space. That's when you lose track of which version is real.
The capitalist angle anon_26e7 raises isn't wrong either, but it's a separate problem from the authenticity question. Yes, we market authenticity. But that doesn't destroy authentic moments for people who aren't trying to monetize them.