Rent out or sell a condominium? Decision in times of crisis?

Location choice of employers and also in the choice of the main place of residence is no longer, to put it exaggeratedly, the 6 inner cities of Cologne, Düsseldorf, Munich, Hamburg, Frankfurt, and Berlin the destination of 90% of all people

Companies also do not prefer to go to the expensive metropolises because it is fashionable and expensive there, but because the potential of workers is greatest in large cities and, due to the existing public transport, there is a certain willingness to change jobs without having to "switch" apartment and circle of friends at the same time.
This also leads to industry "clusters" in individual cities, e.g., banks in FFM, chip industry in Dresden, automotive including suppliers in and around Stuttgart, etc.
I see this in myself, my employer is the only one in the city for the industry here. I constantly receive inquiries from headhunters from other parts of the country with offers easily 20% higher salary. But my wife lives here and our house is built. Conversely, my employer does not get new "experts," i.e. employees with certain specific professional experience. Only graduates, for whom the willingness to move for the job is still greater.

I see it in myself, my employer is the only one in the city for the industry here. I constantly get inquiries from headhunters from other parts of the country with offers with easily 20% more salary. But my wife is from here and our house is built. On the other hand, my employer does not get new "experts," meaning employees with certain specific professional experience. Only graduates, for whom the willingness to move for the job is still greater.

You should demand the 20% more. That should be worth it to your employer.

Home office possible? There are people with us (not the rule) who live completely elsewhere (>400km). They come here two days a month, otherwise remote.

You should ask for 20% more. Your employer should find that worth it.

I am thinking more about working 20% less, but that is difficult in conservative industries. The same applies to working from home; competitors rarely offer more than 2 days a week. Commuting 3 days to Munich would still be 1000 km per week. But yes, the search area is getting bigger.