Comparisons are allowed

And only in the sense that "nothing compares" despite all those examples where the death counts dwarf even the highest suggestions related to the Holocaust.

Holodomor was something like 5 mil I think by some counts but "doesn't count".

The Great Leap Forward was more or less an entire magnitude higher by some reports, 15-55 mil.

As an aside:

Communism, killing communists 5 minutes after the revolution, since forever.