I think the iTunes stuff stays in the cloud as long as one is subscribed to Apple Music & has playlists that are mixed and matched between owned* and streamed? My mp3s seem to still be on my hard drive.

*for values of.

I feel you on pre-pandemic reading brain. Mine goes back to like 2015, but damn. Sometimes I just want parts of younger me back. (Many of them improved with time, but some of them got worse, lol.)