I'm having trouble understanding.
what monopoly? you can choose any of the arbitrary that has the best reviews. nobody has any monopoly. you can defend yourself or hire an agency offering this service... also the one you like, that has the best reviews.
would you? or is this sarcasm? what would stop you? yours truly, who is not a sociopath for example ;)
I agree with the IQ level required. You have to be just right kind of dumb to be programmable to do this job
If we had no police and instead had to hire private protection agencies would you hire one with a reputation for weakness or one that would strike fear into the hearts of your enemies?
If we had no central government to enforce antitrust laws how would you prevent all the alternative protection agencies from forming a monopoly?
Why would they bother to compete with one another instead of consolidating?
You seem to be relying on everyone having what Nietzsche would call a "slave mentality".
The courts have also affirmed the legality of barring those deemed to intelligent from law enforcement.