I want to add here that the Holocaust required a war (the Wannsee conference was in 1942), massive censorship (easy during a war) and misdirection like model concentration camps (Theresienstadt), where international agencies could look around and see how "humane" everyone was treated.

There was no Internet, only official propaganda. Sometimes the truth leaked via the Swedish embassy or railway workers, but it cannot spread far if those who spread it are killed themselves.

But I agree that people all over the world have been docile and compliant since 2020 on all sorts of issues, so the danger is there even if it should be harder today.