> no DJ mixes on Soundcloud
I'd say there's two types of them: independent mixes (someone just recorded a DJ set for the fun of it), and podcast-like radio shows, usually backed by a label. The first group is getting kinda smaller, but the second group is definitely more on Soundcloud than anywhere else -- it's just completely undiscoverable. Sometimes it goes to the artist profile, sometimes it has its own "radio show" profile, and Soundcloud does fuck all in terms of displaying such "podcasts" separately.
For me the most interesting of the platforms in this niche is Mixcloud, whose whole concept is streaming DJ mixes, legally, with some of the money somehow going back to the artists whose records you play. But to negotiatate that sort of legality they had to introduce some rather unexpected restrictions, like how many songs you can play by one artist, how many from a certain album, how many consective songs by artist/album... So it's fine in most cases, but doing something like "best of Daft Punk" mix would go against the rules.
And with YouTube it's pretty much a dice roll. A common tactic is to upload an unlisted blank video with the snippets of the music you want to record yourself playling and see how lucky you get with the copyright algorithm. Sometimes a certain song you want to play is just a no-go, so you have to swap it for a different one before recording yourself, otherwise all your effort goes straight to trash, never to be seen by anyone. And you get up to three strikes in a 90 day period, so you can't be too regular with your uploads.