yes the word matters. nobody here talks of nationalisation. the term used rather translates to communalization.

On a side note: the houses being talked about are currently predominantly owned by large multi-national corps, thus even if it was the national government, that would be an improvement.

But the national government has a lot of money and power, while local and regional governments generally have less.

Anyhow, a lot of the now "private" housing in big buildings in German cities (also former western germany) WAS 'nationalised' until late '90s - '00s. In many cases it was (is) the property of a "city social housing construction/renting company" which has local/regional businesses, banks and political representation on the board. Only the last 20-30 years did these semi-public companies start to sell it all out (after reunification of Germany it sped up a lot). The argument was (and still is) that the renovation of a lot of these 'older' big apartment buildings was too expensive for those 'social' companies to bear, and by selling it fresh private capital would pour in and the old buildings would get renovated. In many cases renters got to stay where they were after sale to private investors for decades still and even keeping their old rent amount for all that time. Until the owner suddenly decides to "seriously upgrade the building": then they can kick everyone out relatively easily and set new prices after renovation. But in reality a lot of those "seriously upgrade" kicking renters out situations was just that: everyone out, a little bit of paint but no serious upgrading, and afterwards every apartment has new rent contracts for way more money. Often also because apartments were split into more units. Result for many inhabitants: being forced to leave the housing they've lived in for many decades, forced to pay higher prices, but get similar or worse housing quality. It's very very reasonable that in cities where this is a very widespread situation, renters are super pissed off at companies like "Vonovia" which dominate entire neighbourhoods and give 0 fucks about renters, only about their shareholders. Germany has a very high % of home renters and a pretty low % of home owners, especially in larger cities.