Construction costs are currently skyrocketing

So it would also be an option to consider that Russia, in turn, no longer supplies "unfriendly states" with selected raw materials?

Basically, I would currently exclude very little completely. On the other hand, Russia has little to offer economically apart from raw materials. And in the medium term, they certainly want to do proper business again instead of isolating themselves like North Korea. But yes, it could also be that certain raw materials are no longer delivered. For example, those needed to switch to battery-powered cars.

Nowhere in Europe, except in Switzerland, is the owner-occupied housing rate as low as ours.

In Switzerland, this is probably due to the imputed rental value. There, you have to tax your saved rent as income, so ownership is financially moderately unattractive.
I wouldn’t focus too much on the owner-occupancy rate here. Even if that might not be the most popular opinion in a home-building forum, I think many people are better off if not almost their entire wealth is tied up in their home. That is simply a nasty concentration risk and the exact opposite of diversification. Also, the illiquidity of owner-occupied housing and the lack of options for partial sales (leaving aside those somewhat dubious providers) are a major disadvantage.

We are supposedly such a rich country.

Maybe wealth is inversely correlated with homeownership? Just a thought ;)

And in the medium term, one certainly wants to do proper business again instead of isolating oneself like North Korea.

With Putin, that definitely won't work anymore. Someone else has to come.

We are supposedly such a rich country. Nowhere in Europe, except Switzerland, is the homeownership rate as low as ours. If you want to get frustrated, you can look up on Statista how high the homeownership rates are in other countries. Bitter.

This is not a new insight. You keep reading it, the reasons are also known and have already been mentioned here... see

The strongest factors for me are the strong tenant rights, the local building regulations, and the demands of the population.

As for Switzerland, it should be mentioned that you have to consider the different tax system. I am not an expert there either. The Swiss have to declare a fictitious rental value for property in their taxes. This must be a minimum value of the market rent. Without checking, I believe around 2/3. In return, you can then deduct interest on mortgages as well as, I believe, other costs. Some Swiss people might not want to bother with that at all and then find renting good too.

That is a very undifferentiated view. In rural areas, the homeownership rate is around 60-65% depending on the federal state. In Berlin, it is only about 17%. In the other city-states, it looks similar, and also in the large cities. And historically, these have been extremely heavily destroyed. The concentration of wealth and thus the ability to acquire property cements the situation. In addition, there has historically been very hesitant lending compared to other countries... the tendency not to move much, but "to build only once in a lifetime"... there are so many factors. Reducing the whole issue to strong tenant rights and high additional costs is indeed a very narrow approach.

With Putin, that definitely won't work anymore. Someone else has to come.

I am sure of that. Russia also needs international trade in the long run in order not to completely decline. Putin has tried quite a bit in recent years to circumvent the existing sanctions to obtain foreign currency. A country that completely isolates itself economically or is isolated will sooner or later become a country like North Korea. And that is absolute poison for Putin and his great power fantasies. He does not want to sit in the second row, but in the front row with the major countries and to be at least on equal footing with them or one step above.

Let's leave the discussion with a political focus alone, otherwise it will quickly come to an end here as well.