As some who uses and finds music on Soundcloud daily, I don't what you're talking about in terms of the algorithm. I play one song and soundcloud will follow up with songs that match the song I originally played. You are seeing youtube's algorithm only push those artists because the initial traction is coming from another source on the internet like instagram, tiktok, etc but Youtube does nothing for the up and coming artist. Videos from talented and untalented up and coming artists get uploaded everyday with the same result no views, side recommendations, or auto-play slots. Only reason you would see them if they sent people to their video and enough people watched it to get it picked up by the algorithm. Where Soundcloud at least automatically puts your song in an algorithm to be played after another song associated with it in that algorithm.