Heat pump, electricity prices, gas prices - where is the journey heading?

I see it similarly. You can calculate a lot, and in the end, everyone calculates it in the way that suits them. Overall, however, it probably won't make as much of a difference as many assume.

I personally also assume that electricity prices will rise significantly more in the future than the prices of fossil fuels. Therefore, I tend to opt for a gas condensing boiler. If it breaks down after 15 years, you can still decide then.

Overall, it will not make as much difference as many think.

Sole heat pump or air-to-water heat pump with COP of >> 4: Yes, worth it. But the ground conditions have to allow it. I could never have done either here myself, even with a lot of money (allowed). No chance. A friend of mine in Thuringia has it. With stars on the house (plaque from the state, award). I believe COP > 5.3. Really good system. The first of its kind in Germany. Brilliant to the third power. But it was not exactly cheap. You invest in heating cost energy or in technology. Warm bottom costs money either way. Freezing and cold water is cheap.

Air-to-water heat pump vs. gas condensing boiler: Basically even at present. Actually a pointless debate.
Everyone can believe what they want, like with solar panels, on these two topics.

I have settled the month of April today and currently pay only 26 euros for my total electricity (household including heat pump after deducting photovoltaics). As far as I'm concerned, the electricity price can double or quadruple in the next 10 years. Then I did everything right.

Of course, the calculation has a catch, because the technology, insulation, and photovoltaics also had to be paid for, but the higher the prices, the sooner the decision to incur additional costs has paid off. In the long run, I am the winner.