People may find themselves in three situations.
‘Coasting’, trying to climb back up to their former position or hitting a glass ceiling.

All societies – past, present and future, were, are and will forever be composed of various mixtures of ‘coasters’, ‘back climbers’ and ‘glass ceiling hitters’.

Please note that I’m dealing in self-referentials here. This is about how individual people describe themselves when speaking to themselves.
The coasters enjoy the life they had designed/expected for themselves.
The ‘back-climbers’ attempt to regain the position/status they believe it was rightfully theirs but had been robbed of in circumstances outside their control.
The ‘glass ceiling hitters’ are… busy hitting the famous glass ceiling.

If a society is composed of a ‘healthy’ number of coasters combined with a manageable number of ‘back-climbers’/’glass ceiling hitters’ then the frustration felt by the latter – which tends to tear apart the social fabric, can be compensated by the sheer mass/inertia of the joy experienced by the former. Hence the society can be described as being ‘stable’.

Whenever the ‘back climbers’ or the ‘glass ceiling hitters’ get the upper hand, things start to unravel. Or to fall apart…

To understand what I’m driving at, please consider the pre-revolutionary Russia and the German society after WWI.

Russia was an extremely hierarchical social organism. The birth-place was ‘definitive’. And most of them led to very unpleasant lives. The vast majority of the population, from muzhiks to intelligentsia, could not break through the glass ceilings allocated to each of them, at birth.

The defeated German population had found itself in a very unpleasant situation. After having been told they had been instrumental in preserving order in Europe – as the back bone of the army who had defeated Napoleon Bonaparte and kept in check Napoleon III, they found themselves at the receiving end of history… After their fathers had witnessed the Parisians eating their zoo animals during the 1870 siege, the Germans were reduced to hunting food scraps themselves.

A horse being butchered on a Munich sidewalk in 1918 or 1919.

Hence the difference between communism and nazism. Both equally authoritarian in nature, each of them springs from completely different social circumstances.
Which explains why ‘progressives’ have such a high tolerance for communism…

While the ‘back climbers’ attempt only to reinstate the order they were accustomed to – order which has already been proven dysfunctional by what had happened, the ‘glass ceiling breakers’ are always attempting to open new roads. Very enticing from the ‘progressive’ point of view…

Fact is that both communism and nazism/fascism are artificial.
Figments of frustrated intellectual imagination.
Both ideologies have been put together by thinkers and only followed by ordinary, desperate people.