Ugh, I was unaware that Spotify bought #WhoSampled (a site I've generally avoided using in any event) last year. Meanwhile, this thread details why certain acts might request their sampling behavior not be catalogued on the site—which is far from comprehensive for this & other reasons.
#FuckSpotify

I know plenty of samples, but since my declared favorite genre of music has for decades been "sample-worthy" (& ideally not yet sampled), I miss the RSFAQ for allowing quick due diligence, etc., & also for discovery of acts w/ good taste. #WhoSampled may have better UI, but it remains inferior, IMO.