Construction costs are currently skyrocketing

But does anyone actually know why? It still feels like the press and co always say "Year-end for 10-year fixed at 3.5-4%!!" or something like that with few deviations, and now it's actually been slowly and steadily going down for a while

First of all, all predictions are at best well-educated guesses. Because everything that is clearly certain is priced in by the market immediately and almost completely. Accordingly, the forecasts by Interhyp, Dr. Klein, FMH and the like are probably more interpolations of the past. Currently, these are mainly recession expectations. When the recession eventually arrives, people also hope for an end to inflation due to falling demand. However, I would not rule out various other scenarios now, e.g. the combination of gas and euro crises. Then everything could develop completely differently.

Hard to say, but it’s going down because market participants’ expectations are dropping. They probably don’t believe that the ECB will carry out the hikes as announced.

The further increases will come, that should be pretty clear after +0.5% instead of 0.25%. But it has often been said that construction loan interest rates do not primarily follow the key interest rate ("the short end") but rather tend to align with the yields of the 10-year bonds ("the long end"). And those are currently losing yield because the recession is approaching in large strides. The interest rates for real estate loans are therefore falling because the economic situation is rapidly deteriorating. But at the same time, the risks for banks are also rising, so they will certainly apply larger surcharges on the interest rates—and will not simply fall back to 2%. The banking lending survey shows pretty gloomy clouds in my opinion, and only a few have not noticed the turnaround in the real estate market. And there is no sign of relief in inflation either.
In any case, exciting times, in the sense of the Chinese proverb..

To cause panic and to get people to close the deal

The press? For what reason should the press get people to close the deal?

Don’t you want to start your own thread, for example titled: "Grundsteuerromantik?"

I already opened a thread for that, maybe we can discuss it there.

To create panic and to get people to finalize [something]

What else is that if not a conspiracy theory?

Encouraging people to finalize financing in order to make a profit is a conspiracy theory?