Also just fun to be a plain-old jockey when you have company over, rather than just let “Appotifydal Top 3”
I also buy a lot of digital music on bandcamp.com, and like OP, host using navidrome.
But you are right, when company comes over letting people DJ is fun. Instead of using my actual CDs, I set up a system with RFID cards. You can buy hundreds of RFID cards for super cheap. I print out the cover art of each of them, and the RFID ID corresponds to an album. A simple RFID reader hooked up to a pi, which reads the ID and plays the corresponding album with mpd on my stereo, makes for a cheap, fun way to allow people to physically explore your collection.
(Un??)fortunately, I am usually the one slinging CDs for people to listen to, people just like being able to offload that and listen to curated music, vs. "throw on spotify whatever" and having it just _play_.