Interesting. Now that I think of it, I do listen mostly to older songs and I do watch mostly older movies. But I don't think selling out is the problem - strong convergence towards "what works" and the risk aversion by big companies have always existed and it's just a part of the natural cycle where some new star creates something nobody's seen before and then that becomes the cash cow everyone tries to replicate.
The problem, I think, is discoverability. Youtube almost never suggests me new songs. Neither does spotify. 20th century was the age of curation - here is a movie premiere, here is a television show, here is a radio song. 21th century is the age of choices - and most people converge towards the thing they know and love.
I think there are a few billion dollar ideas out there that can make discoverability fun and engaging. I think that's partly why TikTok did so well.