I've actually had the opposite success rate going with soulseek. I've been able to find tracks or artists that simply aren't on spotify. For eacmple a lot of Japanese bands that I follow simply don't release full albums on the regular. usually just singles and EPs here and there. I rarely find them on spotify but on soulseek they're on there within the day of them releasing the song. some with other obscure stuff. The soulseek user base is primarily made up of audiophiles so you're going to find a lot more and a lot better quality stuff.