I'm not convinced of this. I spend a lot of time scouring the internet for older songs. Pop tunes, deep cuts, whatever. Much of it is genuinely better. I'm not one of those "nobody makes good music anymore!" but if we're strictly speaking in terms of general pop music, I can't imagine how anyone can can think today is equitable to "the past" (I'm speaking mostly about what I've hear from the late 40's through the early 70's).

In fact I'd argue most of the better music isn't "remembered" at all. You certainly have little niche groups of people who follow everything, but the wider population only remembers stuff like - let's say Janis Joplin for example. But "nobody" would know Judy Henske these days, even though she came earlier, had a similar style, and had better records. Everyone knows Nancy Sinatra, but "nobody" really knows about Lee Hazlewood who wrote her songs, made albums with her, and had a mountain of exceptional work that preceded her.

Plus back then you would have less good pop songs for sure, but there was rarely anything downright bad. You didn't have song after song coming out that was simply offensive to the ears like "All About That Bass" or such things.