There's plenty of good new music out there, it just doesn't chart any more, because the way we consume music has changed
When I was growing up in the 90s, every album you bought was a risk. Even if it was a band you knew you liked, you'd probably only have heard one or two songs from the new album before you bought it, therefore you were taking a real risk by spending your £15 on an album.
So people clustered into about 5 or 6 herds. You had the pop kids, the indie kids, the nu-metal kids, the dance music kids. And in those herds word of mouth would rule, and consensus would form, because you'd only buy something if everyone else said it was good. And so the best songs of the moment from each of the big genres would hit the charts.
There's no risk any more. You can call up any song in a second, for free, there's no need to spend £15 on an album you may end up hating. So the need for the herd doesn't exist. Kids don't like genres any more, they like songs. An average evenings listening for 18yo DD will have her jumping from Placebo to ACDC to Florence and the Machine, to some song from a Buffy the Vampire Slayer podcast, to The Crane Wives, to some K-pop thing, and so on and so on. (And thats just the stuff I recognise)
She doesn't have a herd, there will be noone on the planet who shares anything close to her music taste. Her friends are no more of an influence on her listening than her parents, her Grandad, the TV show she saw last night, a random Twitch streamer, a band she heard in a pub. She has songs in common with everyone, but no common genre. And she's not unusual in this, we're all genre hoppers now.
And because there are no herds any more, there is no consensus, so what gets to the top of the charts is the lowest common denominator, the music that's most inoffensive to the most people. Its not good music, because good music is divisive. The stuff in the top 10 is being listened to by lots of people, but I doubt its their favourite music. Thats why you can get to number 1 with a 100th of the sales you'd have needed 30 years ago.