Somehow, 8tracks was different, I could pick a genre and I'd just listen to a whole playlist of mostly new, great songs. Likely because it was curated by DJs and musicians themselves, not record labels or algorithms. Second, because there's a lot of upcoming talent that's not on Spotify yet for lack of an album or label, but had a single mixtape or single record out on e.g. Soundcloud which was great. I don't know the exact mechanics, just that it was the best place to discover new music for me, and I haven't seen a good replacement yet.

So for a few years if you wanted to share a playlist this was THE way. The early day of Spotify also had a limited library and not a lot of people used it.