Is the world becoming uninsurable?

Not uninsurable, but buildings are going to have to become tougher.

It's happened before. Chicago's reaction to the Great Fire was simple - no more building wooden houses. Chicago went all brick. Still is, mostly.

The trouble is, brick isn't earthquake resistant. Not without steel reinforcement.

I live in a house built of cinder block filled with concrete reinforced with steel. A commercial builder built this as his personal residence in 1950. The walls look like a commercial building. The outside is just painted cinder block. Works fine, survived the 1989 earthquake without damage, low maintenance. It's not what most people want today in the US.

If the market is allowed to price insurance correctly then we can motivate building designs to be more disaster resist. If the McMansion can't get insurance but disaster resistant, modest homes do, then people will adapt.

"Correctly" is doing a lot of work here. Some readers might miss that this is double edged. Insurance is a mandated product. You don't have a choice if you want a mortgage, or want to run a business. So while it is true that the sustainable price for insurance in many areas is higher than what current regulations allow, let's not forget what happens in an unregulated insurance market; price gouging.

For what it’s worth, you can get a house with no insurance or mortgage. They tend to be cheap. I had an uninsured thatched cottage for a while, it was 68k

You can have a mortgage with no insurance (after purchase day) here in New Zealand. The bank won’t like it, but also won’t know.

You are right that you can get away with it in NZ.

For total loss then bankruptcy might save you money (assuming you have no other assets or kiwisaver; since you still owe the debt).

But part of the contract with the bank is allowing the bank and insurance company to verify/update.

If you cancel your insurance, the insurance company is incentivised to tell the bank since you will probably sign up for insurance again when told to by the bank. I don't believe the banks or insurance have push updates. I would guess banks batch check if insurance is still live annually?

I live in Christchurch and I believe insurance is valuable risk management - plenty of people gambled and lost with Earthquakes. That said: I own an as-is house because I bought a 3 bedroom on 800m2 for $190000 (cheap because you can't get a mortgage for it because it is uninsurable due to subsidence - I only paid land price).

(For those unfamiliar - $190000 New Zealand is roughly $106,000 US, and 800m2 is about 1/5 acre. I know neither Christchurch real estate nor its geology - but obviously that 1/5 acre carries a big "will it keep subsiding?" caveat.)