Construction costs are currently skyrocketing

It already starts with the fact that what a central bank can create electronically is not money that ever reaches the pockets of citizens. For that, it would have to physically print and distribute cash.

This again shows your gaps in knowledge. You might score points with this at the pub, but in reality, no physical cash is needed. Central banks are actually not the ones who truly create the money; that happens in commercial banks (savings banks, cooperative banks, private banks...) by granting loans against which only a partial balance of the bank stands (practically so little that you can roughly set it as "nothing"). The money supply in circulation is thus strongly controlled by interest rates. At low interest rates, many loans are granted, and thus a lot of money is created. An interest rate increase has exactly the opposite effect.

And the connection between money supply and inflation is so thoroughly empirically disproven…

Nothing is disproven here, only not reasonably demonstrable in practice. However, the connection is so obvious that it must have a kernel of truth. On the one hand, we have different money supply definitions that have different impacts. On the other hand, you have the problem that a) effects often occur with a time lag and b) market participants do not work with perfect information, and this information neither spreads immediately nor evenly. Information spreads in waves (Robert Shiller likes to use the word "epidemic"... he had already completed the work on "Narrative Economics" in 2019...). These waves can then also generate their own shocks, but also spirals. If you then look back with a fully rational perspective, of course no direct connection to the money supply emerges anymore.

At low interest rates, many loans are granted and thus a lot of money is created. An interest rate increase has exactly the opposite effect.

Is that true? Whether I have 100 loans with €10 interest or only 10 loans with €100 ... I end up with the same, don't I? fail

Whether I have 100 loans with €10 interest each or only 10 loans with €100

100 loans of €1,000 each with an interest rate of 1% is naturally equivalent in burden to 10 loans of €1,000 each with an interest rate of 10%. But in the first example, you take out loans totaling €100,000, in the second example only €10,000. And thus, the money does not multiply as quickly anymore.

100 loans where the bank makes 10€/month each = 1000€/month. 10 loans where the bank makes 100€/month each = 1000€/month.

Und somit vermehrt sich das Geld nicht mehr so schnell.

The ratio to time also remains the same.

It is about the loan amount. And that naturally depends heavily on the interest rate given the same installment. As many home builders have just had to learn the hard way. They are no longer building, so the money doesn’t circulate through the construction companies either. Even if they were to build smaller as you assumed and could therefore reduce the loan... not many more people will take out a construction loan to compensate for that. Rather the opposite, rising interest rates affect everyone. Some can no longer afford it at all, some can only build smaller.

Some can't afford it anymore, some can only build smaller.

Then example calculation with smaller volume (money and house).
Earlier:
600k€ with 1.2% interest = 600€/month interest
100 people: 100 * 600€ = 60,000€/month

Today:
300k€ with 2.4% interest (fictional as example) = 600€/month interest

Or to extend your statement, and some can still afford this interest (I would be interested in how many still borrow 600k€ at 3.5% interest)
Then the sum mixes:
A few:
600k€ with 3.5% = 1750€/month interest
A few more (build smaller):
300k€ with 3.5% interest = 875€/month interest
Out of 100 people:
10 * 1750€ = 17,500€/month
50 * 875€ = 43,750€/month
40 (can no longer build)
= 61,250€/month

Interest per month remains the same