They happen, far and few in between. You see it mostly with drug dealers who also pimps.
Must emphasize, the pimp section, drugs alone is not enough, the pimping builds out the user network.
Based on Tp4's studies of known acquaintances, in general, no one wants to be friends with the drug dealer, except drug addicts, who are largely social dead ends. PIMPing, extends and utilizes those dead ends. Just about every male wants to be friends with at least a few Pimps.
No other business can start super low and have traction without modest funding. Ironically, restaurants are a far more unstable business compared to drugs/pimping.
The very successful ones, move on into nightclubs. Then they hand off the drugs to the small time runners and just take a cut. This preserves deniability as the club owner.
The pimping part, they usually keep close, it's just handy is what Tp4 was told.
It's not a super easy job, high eq requirement, modest intelligence, absolutely 0 morals/conscientiousness.
Not a common archetype. The luck part comes in, you don't get murdered while building the initial stash in a drug feud, it's very rough due to the high crime locations where you start out.
Very important, you can't start out as an addict. You'll almost never make it, you can only become a drug addict much later in the career.