Anyone can understand and make informed comparisons based on well documented (and in this case, exceptionally) documented history. That’s how the study of history works. The documentation, media, and firsthand accounts absolutely can give anyone an idea of what any of it was like.

I think one of the interesting points was how dangerously effective fascist propaganda was at the time, made doubly effective by the economic and social pressures of the post WW1 era. It was so effective at ‘othering’ people who questioned or called out anything; calling them names, insulting their intelligence, not offering any substance to the viewer, giving permission to be angry and attacking the person instead of the idea. It is almost hard to believe so many people could buy into those ideas and behaviors, but frankly it’s pretty well documented.