As a teenager of the 70s, I'd like to say that there's loads of good music around now - but, when you're not young, you don't know where to look for it. You hear the chart stuff in an Uber, and you think that that's what modern music is like.
I recently looked at the singles chart for November 1973 - the year of some of the best albums ever made - and the Top20 was just dire.
Also, kids don't consume music the way we did. It's not the radio and record shops. So unless you go through the same channels as them you'll never hear the interesting, innovative, moving, well-crafted stuff.
How do I know all this, given that I'm ancient? I like my daughters to choose half of the music that's played in the house and the car. Which means that I hear a lot of modern stuff, and they're big fans of XTC.
As to the worst decade...I'd say the 90s were patchy, at best.