The real reason "music is getting worse" is that some people think so.
Others do not.
That’s it in a nutshell.
Some people thinking so is not enough to make it reality for all.
Not even just with music. There is a significant "cult mindset" out there that absolutely believes their judgements are universally correct and that others with different views are wrong. Not just wrong, but perhaps even obstacles to be removed as well in some cases of particular concern in order to get one’s way.
IT happens!
Let’s not think that way about music. There is plenty of diversity in music to go around. Enough that almost all like some. It doesn’t matter what others think, other than the masses will largely determine the market for music just like everything else.
Personally, I am finding more music both good and bad to try out than ever and that is a good thing!
Besides, most of the "good old stuff" is still available, including remasters and remixes that offer a new spin on something old, and same will hopefully be true 50 years from now if we make it that far.
Ever marvel at how far 8 basic notes to work with has gotten us? I guess we have to run out of new twists eventually, though in lieu of doing the math, the possibilities do appear endless for all practical purposes. Well done!