I’m formerly Catholic, and the explanation that I read/was taught, was that Satan was the dictator/jailer, at least more so than a directly sadistic tormentor.

And despite not directly being a god, I can’t imagine many people willing to take their chances against a divine figure powerful/intelligent enough to challenge God. An especially a supposedly omnipotent, omniscient, omnipresent one.

Also, that even though God and Satan despise each other, God still needed Satan to act as a jailer.