Ex East German here. I think you are mixing a few terms. Polarization, dissatisfaction, inequality - those are different things.
Also, at least for East Germany - no idea how it was in Russia - when they showed the houses of the powerful (Wandlitz - https://en.wikipedia.org/wiki/Waldsiedlung - You can google for some images of the houses and facilities) even back then in 1990 when I saw it on TV I thought it wasn't really much. Even a middle-middle class American or West German lived better.
The differences were not as big as with billionaires in the mix. It wasn't like in some African dictatorships where the top really had so much more. The GDR elite lived better, but far from extreme luxury as far as I could see after the reunification. I felt zero envy after I saw it even retroactively, I had already seen much better in average West German houses that I had visited by then.
Also, again speaking for East Germany (I was 17 when the wall came down and participated in some of the events), I don't think the term "polarized" applies. I mean, we even had am entirely peaceful transition even though one party had all the weapons and the courts and the ability to use them. Still, they were not crazy and/or angry enough. and actually opened the wall instead without much fanfare.
Not sure what would happen with an actually polarized situation, like between some of the camps in the US, if one side had both the means and the legality (full control of police and courts to do as they wanted) in a situation where they would have to give all of that up.
In East Germany We didn't even have anyone drive a car into protesters or anything. That kind of hate between the people just wasn't there.
In practice the USSR was an extremely unequal society in terms of wealth distribution. Growing awareness of the enormous gulf in the standard of living and political power between the nomenklatura and the quasi-enslaved contributed substantially to its collapse.
I do not know about USSR, but AFAIK at least in Czechoslovakia the communist leaders do not really have big personal property. They have enormous political power and also access to property through their functions (assigned appartments and official cars), but not in form of direct ownership.
That is fair. But by similar logic, some medieval lords technically also owned nothing. They merely were administrators for the king's land. And yet that position enabled social and political connections that translated into fabulous wealth. The ability to control the disposition of nationalized property as the Communist leaders had, was a form of wealth, in my opinion.
Everyone was always satisfied with the ruling party all the time. It was great joy.