Tough question cause it's hard to know what you mean by "dead". I'm too young to know first hand but I've heard that when coke really started making waves in the late 70's early 80s that I'm sure heroin sales weren't as great. But at the same time there was still a ton of addicts on dope buying heroin throughout the 70s,80s90s,00s.. you name it. And I'm sure there was some crews or groups of criminals who were becoming very rich still off the heroin trade in the 70s and 80s... cocaine just got that huge widespread hype that came with it with all the studio 54 shit and rich people doing it. Also claiming there was studies that doing a line of cocaine is no more addictive than eating an m&m.. really funny few years later the crack era hit. Pretty sure I've never seen someone give away their car for a bite of an m&m. Interesting stuff though I would like to know more