Hybrid heating: Is a heat pump with a gas condensing boiler sensible in old buildings?

With high heating load and high flow temperature, the efficiency of a heat pump is simply poor.

Predictions are difficult, especially when they concern the future ;) So I simply approach the matter freely based on Taleb and Occam with as few assumptions as possible. In winter, the sun shines little and is low, so photovoltaics are to be forgotten. In addition, we in the south often lie under fog, and in winter, sometimes no sunlight is seen for 2 weeks. Sometimes there is wind, but often as a storm and also bad. The electricity would therefore have to come from the windy north, but the lines there struggle with citizen initiatives in every second village. Wind turbines, by the way, also. What else remains? We are currently shutting down nuclear power, hydropower is considered "renewable" but today you no longer get permission to flood an alpine valley in an environmentally friendly way. German geography doesn't offer much anyway, even if you wanted to. Basically, you also have the problem that you have to massively oversize unreliable energy generation like sun and wind (expensive and not exactly ecological) so that it is sufficient even in unfavorable cases. Even with storage at the network level (also expensive). In the end, only coal, gas and buying electricity from the neighbor remain. Everything else expects miracle technology. Expert opinions are fine, but healthy doubt is also important.