Here's a politically incorrect take: In the Hui Jian 徽剑 kidnapping and murder case, the hired criminals were at the bottom of the underworld food chain.
Many hitmen and kidnappers aren't the professional career criminals outsiders imagine. A lot of them are just temporary freelancers taking one-off jobs, and they get heavily skimmed by layers of middlemen.
In a sense, the emergence of 'guarantee groups' 担保群 has made these commissions more transparent and efficient. That's why I say these cyber tools have modernized the underground world.
This is also my anthropological perspective.