Yes but why are we required to imagine only this? With this logic, why won't we try to imagine how bad Stalin's (or Hitler's, or anyone's) reign of terror would be with state-controlled social media? With state-censored Internet (that's about current Russia, by the way)? With modern communication technologies et al. and so on?

Hell yeah, let's go back to the caves just because science, technology and progress can actually empower everyone, including dictators, maniacs, psychopaths, predators and "bad people et al.", not just "good" (the definition of "good" varies, but let's assume we're using common principles of goodness) people.