It seems the supply of people willing to risk a long-term incarceration for short-term gains is basically endless. And the ratio of those who then get greedy, and/or don't want to silently exit is also seems to be high.

That said, there are probably many-many thousands of people who are ex-dealers. And we'll probably never know about the ex-online-dealers, who had sufficiently good OpSec. (So maybe in 10 years we'll hear about some people who heard about those who did it for a few years and then silently quit.)