You keep missing the point here which has been explained by several people already. But I will repeat is once more so you may finally understand it: a heatpump can only work for a home that is well insulated. In many countries that have relatively mild climates (like UK, NL, Germany), homes (especially the older ones) are not insulated well enough to be heated with a heatpump all year long. It is logical that you see heatpumps in countries with colder climates because those homes are way better insulated already and thus suitable for heating by a heatpump.
So this is not entirely true. Heat is heat at the end of the day.
You can make a heatpump work on a poorly insulated home, but it will need to be much larger and the radiators will have to be large to get the required room heat output. The challenge is the heatpump output power will begin to decline as the outside temperature falls, so you end up with very large heatpumps serving just a few days a year - and heatpumps don't run as efficiently when cycling or running at lower loads.
There is no reason a heatpump cannot work on a poorly insulated home. You can just put a bigger and bigger one in. Unfortunately, a 24kW boiler costs about £2,000 but a 24kW output power heatpump costs about £15,000. Not economical.
So instead you sometimes see "engineers" try to fit the 12kW heatpump and people complain their home takes forever to heat up (or is too cold in winter.)
A few things need to change for heatpumps to be more economical. The price needs to fall drastically. They are a motor, refrigeration system, controller. Shouldn't cost that much. And the installers need to get better. The scheme around F-Gas in this country is a bit bizarre and segmented and too few people do air con systems.