Heat pumps are no more fragile than air conditioners.

Yes, and that's why I have none.

No fridge? That's a heat pump.

Not everyone lives in an area where they can afford not to have one, especially with climates changing and temperatures hitting higher/lower extremes.

It all comes down to building techniques, insulation, airtightness, eliminating thermal bridges, &c. There are also many low tech solutions for heating/cooling, such as air/air heat exchanger couples with ground/water or ground/air heat exchanger at a fraction of the price and a fraction of the maintenance.

Of course the average american living in a mcmansion which wouldn't pass regulations in 1992 Poland cannot use such solutions, but really it isn't a problem of climate, you'll find passive houses from africa to norway and everywhere in between, most of them without heat pumps

Which are famously reliable and cheap to service...

In my experience they are quite reliable if they are quality brands. My parents have central AC for 20 years with no need of repairs

Thwre is nothing voodoo about heat pumps. Not really that complex and not at all fragile either.

Heatpumps are a proven technology, have been in use for more than a hundred years, and are one of the most efficient (and thereby cost-effective) ways to manage heat.

They're also technically simpler and have fewer components that can wear out. And they're a single system that works both for cooling and heating, rather than needing multiple system investments.

The majority of experts believe that its the future technology stack to manage heat, not a gimmick at all.

That having been said, always start with good insulation first.