Cocaine is very much being cut with fentanyl. About one third of the cocaine overdose deaths last year were from users ingesting cocaine laced with fentanyl.
https://duckduckgo.com/?q=fentanyl+laced+cocaine+deaths&atb=v1-1&ia=web
Hadn’t heard about that, but that’s even stupider. At least heroin addicts might be wary of it; cocaine users are going to be totally off guard.