I think that's because the playbook for a successful totalitarian regime is a function of human nature, and regime stability is probably maximized by a fairly s

I think that's because the playbook for a successful totalitarian regime is a function of human nature, and regime stability is probably maximized by a fairly specific set of parameters. Eg. optimize by turning the propaganda visual style knob to realist-severe-deco, the secret police knob to incredibly brutal, the national culture knob to leader-deification, etc. And this will work until the nature of the human animal's tribal/lizard brain changes (hint: ~never).