I’m not convinced that it’s any easier or harder to live authentically now than in any other era. Being “Real” always takes a great deal of willpower. Think of the Inquisition, or of McCarthyism, or the Cultural Revolution. Think of Janucz Korchak and his children singing on the way to the death camps (WWII). It’s hard to claim our own era is more inimical to authenticity than any other.
I do think that one peculiar feature of modern times, however, is the overwhelming prevalence of fake authenticity –where the appearance or the pursuit of what is “authentic” becomes itself a locus of artificiality. That’s probably a side effect of commercialization, wherein “realness” or the convincing illusion of it becomes a commodity that can be profitably monetized.
That said, it’s also worth noting that one can be authentic even when playing a set role –think about any truly great actor.
For these and other reasons, I personally lean away from Sartre’s authentic/bad-faith dichotomy. In my own rendering of existentialism, the key tension is between being true (authentic, as it were) to your own self-identity and being a productive member of a functional larger community –two ends which are each positive in themselves, but which continually and inevitably come into conflict.
As a Christian existentialist, I resolve this tension in a religious context: “Develop your talents, and put them to work in service to others” –a gospel-inspired synthesis of individuality and community.