The spotify daily mix thing, I get you on that, I miss it too! I honestly just browse rateyourmusic, acquire them via soulseek, and hope for the best. As I said, I have more than enough music to last a lifetime, but for those who don't have a great library already, I think some of the fun of music comes from the process of discovery too!
But as to making my music externally accessible, I mean, it is at least secured by a basic auth page, and I mean, what would a bad actor want, to sabotage my music collection? It would suck, but I mean, wouldn't be the end of the world. I have it routed behind caddy and a cloudflare tunnel, so the only threat in this circumstance is someone who has access to my home.