I'm using navidrome and symfonium and tempo, symfonium is worth to pay for, it does offer support for other protocols to plu into. What you could do with navidrome, is to create a m3u playlist of your random stuff, either manually or a script that would keep the playlist updated.
Mostly these systems are based on organizing by tags/artists, if you really want the "old school" folder approach then you, I suppose, keep looking.
Or see how to get ehat you want with music library systems