Some needed him and his services.
If he vanished, then his business would soon fall apart.
It would be difficult to rebuild from nothing, even if his people under him decided to attempt to take over and rebuild.
If they were unable to do that, then those who relied on him for various things would start to feel his absence.
A void would be created where he had previously existed, and there would be those who would be pulled into that void voluntarily or involuntarily.
Those who would be drawn to the void that had been created would try to fill his place, or they would be people who would be unable to rely on his business anymore, and that would cause them losses.
There may have been other underworld influences that would wish to take over that kind of business themselves, resulting in them getting pulled into it.
If there were more than one of them, then those influences would likely clash as a result of that.
