Another factor is surveillance. Government state in first-world countries can spy over every citizen right now with millions of video cameras and cellphones, finding outliers with big data technologies and AI algorithms. So-called terrorists. Third-world countries don't possess those technologies yet, but they are coming and probably will rent software (so first-world countries will have even more data outside of their borders).

I can't imagine how someone would organize protests under real totalitarian control, when every step is recorded and you can't hide. They will be arrested pretty soon. So 21-century will allow totalitarian regimes to thrive, unless they are not friends with closer supercountry, in that case of course they will be overthrown and replaced with loyal ones.