This is a really interesting read. But it doesn't answer one question I have, which is why can't Sony or Apple or anyone else bring back decent MP3 players? None of this technology is lost, and there are plenty of small-time two bit no name players out there still making them, often in a much smaller, much slicker form factor than than the original digital Walkman or iPod. If I want to buy a new MP3 player, I have to…
MP3s have been on the way out for a long time, being replaced by music subscriptions. And "MP3 player" is a feature of other devices, not its own device. Both my Apple Watch and Garmin watch can store and play MP3s without a phone; both also support music subscriptions. The only market is in the "enthusiast audiophile flac player thing that costs way too much", just like it is currently for vinyls and DVD players.
I both have music subscriptions (Spotify for the wife, Qobuz for me: Qobuz streams lossless but sucks for music discovery) and good old files (mostly FLAC files indeed except some very old, impossible-to-find, live recordings I only have in mp3). One does not prevent the other.
Also some people self-host or partially self-host things: you stream from a server you own: be it family pictures (I'm Mich / immich), movies and/or music (Plex or Jellyfin). And, well, the stream doesn't spring out of thin air: there are good old files on the server.
Lastly: some music streaming services allows you to buy albums and/or individual songs, DRM-free.