It’s worth noting that a major confounding factor is that, unlike most cities with a housing crisis, Vienna is well below its population peak and so does not need to build nearly as much housing
Technically yes, but lol no. Population is about the same as at its peak and density (person/m2) was about four times that of today.
https://de.wikipedia.org/wiki/Schlafg%C3%A4nger
https://www.demokratiezentrum.org/wp-content/uploads/2022/10...
During that peak Vienna’s housing situation was infamously bad though. You’d have single rooms shared by multiple families and beds being used by multiple people on a timetable.