Disc rot. [https://en.wikipedia.org/wiki/Disc_rot] It's the same problem I'd been having with many of my DVDs and audio CDs. Meanwhile, my old vinyl records - some of them inherited from my parents - still play, for the most part, pretty well.
Sony gave us the CD back in the early 1980s [https://en.wikipedia.org/wiki/Compact_disc] and I can remember the extravagant promises that were made about the digital compact disc's durability and longevity. Now I'm wondering if it's time to just cut my losses and toss all my old optical media in the dumpster.
I can watch videos and listen to music on streaming digital media and downloads now. Of course, the continued viability of those media depends on the survival of the technological infrastructure that they inhabit: successive generations of computers, mobile devices, music players, and so on.
I'll confess I have a certain sentimental nostalgia for vinyl - but my reasons for keeping up my vinyl collection are pragmatic. I want a record that'll damn sure play 10 or 20 years from now. I don't know that about my digital tracks, and I certainly don't know it about my CDs, but I know it about my vinyls.
And as for Sony - the folks who brought us the compact disc in the first place - what are they up to these days?
The tables have turned ... at 33 1/3 rpm.