Well, not really. Under prohibition organized crime made so much money that by the time it ended they had huge amounts of ill-gotten capital to invest in more lucrative enterprises.
Which is the Mafia basically owned NYC in the 1970s, with the Gambino family pulling in an estimated $500mm per year. And that was back when $500mm was a lot of money.
But I do agree, and have often argued, that making drugs illegal is what raises the price and makes it an attractive business for organized criminals.
Too bad the War on Drugs has already financed all the Cartels to the point where they have become ubiquitous in America.
What makes drugs attractive to organized crime is profit. Profit requires sales, which comes from demand.
Nothing is being done to address demand. If anything use of these drugs is being encouraged.