Not "just" survival bias.
I think it's quite reasonable to take a position that there was more innovation and creativity in pop music in 1950-2000.
As the genre has matured, popular/commercially successful music has depended more and more on fewer and fewer producers.
Indeed, there are fewer commercially successful artists: the US Billboard Hot 100 Top 20 this week contains 3 tracks by Justin Bieber, 2 by the Weeknd, and 2 by Drake. That would have been unheard of.