Vienna is quite of an outlier in the EU and even in Austria itself. Here's why:
Firstly, social housing there is a very old concept, and because of that, a significant portion of the population (>50%) already lives in social housing, meaning most the population has skin in the social housing game so they make sure to vote themselves a great situation because they're the majority and that's how democracy works.
But if the amount of population in a city living in social housing is way below 50% (most of Europe) then they don't have the democratic political leverage to vote themselves a better public housing situation, so social housing turns into a low quality charity for the poor and ends up turned into ghettos leading to a bad image of social housing leading to people to further voting even less in favor of social housing not wanting more ghettos.
Vienna, having the majority of it's citizens in social housing for a long time now has reached "escape velocity", that's why it already works there but won't/doesn't work in other EU cities who want to try it now, including in the rest of Austria where social housing is not the norm but more of a safety net for poor people. Other Austrian cities have even sold off a lot of their public housing stock to private investors in the 2008 crisis (cough-corruption-cough), meaning replicating Vienna's success today would be impossible as no city could afford to buy 50% of all private housing at market prices today even assuming private owners would want to sell in the first place.
And secondly, unlike Zurich, London, Amsterdam, Berlin, Luxembourg, etc., Vienna is not a tech-hub or corpo-hub for big international companies to set up large offices of well paid workers from abroad there, and neither is it a low-tax/beach-front destination for wealthy digital nomads, so there's not such a big pressure on the rental market from overseas workers with huge salaries pushing up rents and gentrifying everything.
That's the situation for rents. But the situation for buying a property flips on its head and makes Vienna one of the most expensive cities in Europe for buying your own property, far disconnected form average wages that almost nobody could afford to buy something.