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.

Resistant homes will pay nearly the same prices as everyone else. So the cinder block home owner is subsidizing the sticks houses.

Same happens in autos. Monitored safe driving nets at most 10-20% discounts. Biggest factor is age, and even then, difference between 20yo and 35yo driver is 38%.

There are no tricks or deals to insurance.