And why most is utter dross. People still buy millions of classic albums from the 70's and 80's, in 30 years time very few artists will have that same comfort.
We are only listening to the best stuff from the 70s and 80s, and in 30 years people will only listen to the best stuff from today.
Now, I think a major difference will be the "best" music people will be listening to will be very different from each other. 30+ years ago the popular music people listened to on the radio or MTV was much more broadly known and shared than music today, whereas today different demographics have increasingly siloed music tastes.
I hear a lot of good stuff my teenage sons play on Spotify that I would never hear if it wasn't for them.
There are artists that can publish work now, thanks to the internet, that publishers wouldn't even dream of going near let alone giving them deals. I really like microtonal electronic music for example, not exactly radio friendly.
I don't really think all new music is bad, just most of it. The same could be said for back in the day though. Metallica is a bad example for you to use cause they are still widespread because they are really good. There are other bands you haven't heard of from the 70s and 80s.
This "all new music is dross" argument is repeated every generation as new music out-ages the outgoing generation.
Of course there are bands I haven't heard of from the 70s and 80s. That doesn't mean the ones I have heard of are relevant. It means they're memorable.
unrelated but I love your username.
I bet they feel just terrible to only be making money off of people buying their music, but not paying attention to their opinions.