Music library disappearing on iTunes/Apple Music

This is more of a mystery that I'd like to brainstorm with folks....it's an old issue that won't be resolved because I recently wiped and recycled the MacBook Pro in question...but I had an issue with iTunes that turned me off of the software for music management for me. And now I'm looking into possible alternatives to Apple Music as my main digital library/archive.

In January of 2019 I opened my computer and all of my local music files (music uploaded to my computer from cds, etc.) were gone. Not present in my library interface and I could not find them anywhere on my computer. All of my music that had been purchased on iTunes was in my library, in the cloud, but not locally downloaded (with the cloud icon next to it). So I had to re-download all of my iTunes tracks from scratch again. But at the end of the day I could never find any of my local files (not iTunes tracks, but music I had hard copies of) again!! I ended up taking it into a repair service and they couldn't locate those files either.

I was traveling while this happened and had spotty wifi. I'm assuming there was some kind of software update. I am still having a hard time understanding how that could have happened. Even if I had gone in an deleted all of those files on accident (somehow?!!) I feel like it would've been in my trash, not permanently deleted. It was about 250gb of tunes total. Most of this was backed up on a hard drive (and I have all the cds still).

Basically I'm just still stumped after 6 years lol and was wondering if anyone experienced the same thing? I now worry about using Apple Music as my main library for music.

Thanks!

E