Even though I have spotify, I prefer to listen to my own mp3s. The only time I use spotify is when someone says, "You should check out <band or album>". I'll listen to the album a few times on spotify, and if I like it, I will buy the album and then listen to my own mp3s.
I also own physical copies for vast majority of the music that I download but I basically only buy them to support the artist and to read the booklet.
Seeding, uploading and staying in it for the long haul is a lot more work than just buying a Spotify subscription and certainly not for everyone, but as someone who is constantly disappointed by the selection available on streaming services and also need local files for DJing, I couldn't imagine living without it.