It's just not common in Germany to buy apartments. People either rent, and if they want to buy, they buy a house. Most apartment buildings belong to big companies and not to smaller landlords, making it also not cheaper or in any way attractive to buy an apartment.
In Eastern Europe apartment ownership is very common on the other hand. All the old Soviet blocks have individual ownership of each apartment in it, and the buildings are maintained by groups of people who own the apartments in that building (I forgot the word, not a native English speaker, sorry. But basically like a union out of each owner in the building, there's monthly meetings to decide stuff etc). Landlords usually will not be big companies like in Germany, but just private persons who have had the apartment in their family for a long time. This also makes it easier to buy an apartment, if you don't want to rent.
It's just very different structures and mentalities. When I still lived in Germany I found it stupid to ever buy an apartment and would have just rented forever, since house prices are astronomical. Now I live in Eastern Europe and it took some time to adjust, but it's really just the norm here to buy or own an apartment at some point in your live and most natives I know here own one, or live in a place that a family member owns.