I have issues with Plex regularly with file formats not playing nice, incorrect box art, content being labeled completely wrong, and random server hangs. It's OK, but I wouldn't say it's more convenient than Spotify. With Spotify I do literally nothing. With Plex I have to troubleshoot now and then. I don't see how self hosting a media collection is more convenient in any way.
I haven't had an issue with server hangs or file formats (not suggesting that those can't exist), but for metadata I'm in the habit of putting all music I buy through MusicBrainz Picard which can automatically fix any errors or missing metadata fields and put them in a neat structure (Artist/Album/Song). Haven't had to manually fix any matches since that.
But yes, if you don't have to do anything to have an enjoyable experience on Spotify, then there's no reason for you to bother with self-hosting.
Gosh, I used to fuss over metadata constantly back when I managed my 500gb library of music. MusicBrainz would frequently mess up fields like composer, album artist, and especially remix credits and formatting of the same (using brackets instead of parentheses, "Rmx" instead of "Remix," etc)
I would go on weekend long binges of cleaning up the mess. The neurotic side of me misses having the busy work, but the practical side appreciates having the free time.
