I disagree, there is great music, you just have to find it and not expect it to be served to you. It is one of the most subjective forms of creativity we will experience.
One mistake is confusing radio listeners with music listeners, they're not really connected.
I was spoiled as I was an impressionable tweener when rock and roll emerged and a lad of 16 when it changed forever for me with the British Invasion. It was all coming so fast and so much of it that I could hardly digest it but I could not get enough of it. It was a time in music never to be matched again and if you were there you were spoiled.
Then FM came into reality for more than elevator music and the Album Oriented Rock format was born and the second major music changing event had happened with the first one still fresh and new forms of rock, progressive and metal, were emerging and there was an abundance of riches.
The third wave has been the emergence of streaming and the focus has returned to the 50's with songs being the 45's, the album does not exist as it once did.
I spent most of my career working around much younger people so I was more aware of the current trends in music and I can recall them saying there will never be 80's oldies as the Oldies format was beginning to emerge at that time. Well, they were wrong.
When Rock morphed into Grunge, I couldn't stand it and never gave it a chance but I could not relate to it and the destruction of the tried and true rock composition formula was heresy. Later, as I did with the 80's and emerging Alternative music, I opened my ears and my mind.
Every generation detests the next generation's music, my parents didn't like mine and we didn't like Rap and break dancing when our oldest son got into it. "What the hell is that? That's not music, that's crap". Every generation could sell that on a t shirt.
My contemporaries are shocked to know this old rocker spends the majority of his listening time to forms of Electronica, House, Trance, Chill, EDM and Alternative. I don't do Oldies or Classic Rock except on rare occasions because I do not agree that the music died, it just changed.
We made a big deal out of 500,000 people gathered for Woodstock and most are unaware of the 1,500,000 gathered for a DJ Rave because the one thing that hasn't changed about music, it is communal, it is tribal.