They want total control, not bribes.
One of the more medium size cartels, Jalisco New Generation, specializes in training assassins against their will. Let that just sink in. They do this by advertising jobs, kidnapping the people who show up to interview, and then torturing them in horrific ways until they get the total compliance of learned helplessness. Then they send them on suicide missions.
I don't want to go into the details of the torture because its bad stuff, involving cannibalism even. If you are morbidly curious there's a couple interviews with survivors you can find somewhere on youtube.
And this is far from the only instance of this sort of thing. Sinaloa has been known to kidnap entire buses and make folks fight to the death, winner gets the dubious honor of becoming a member.
These are people who assume every single person in their world is plotting to overthrow them in an instant, and leave nothing to chance vs that. They don't want to hope their bribe is enough to keep you loyal, they want to know you're loyal because you've seen them torture to death countless people. You don't get any agency in the matter.
I have friends that live in Mexico so we talk about it fairly often as well. One of my friends in particular is a wireless business owner with customers near Brownsville/Matamoros, where those telcom engineer kidnappings happened, so he's acutely aware of things.
[1] - https://es.insightcrime.org/wp-content/uploads/2020/06/Mexic...
This sounds like:
1. Just a rehash of the original Hashashin tale.
2. A spooky story cartel members might tell.
Here you go: https://www.youtube.com/watch?v=ZxP-TMArlV0
This is far from the only source you can find that supports what I'm saying. Search for CJNG to find more about them. They're sort of the Phoenix that rose from the infamous Los Zetas.
Why would an engineer willfully take a cartel job, when there is a high risk of them killing you instead of paying you, and killing you by cutting off your face just because they were bored and disturbed? If a cartel even offered me a job, I'd fear for my life.
These people really are as bad as it gets. You don't want to be anywhere close to involved with them.