Natural disasters are force majeure and usually not covered, and for those policies that do cover them, they have actuaries (data scientists) making sure that the loss of disaster is lower than the expected premium plus investment earnings earned.
Furthermore, your insurance company doesn’t always hold your policy any more than Walmart makes your Nintendo console.
Many consumer insurance companies simply resell the risk of the insurance to an even larger company.
The insurance industry has enough money to pay these sorts of things off because people pay a ton of money for insurance, and not just health insurance.
In the developed world on average 9% of all the income of every dollar spent in an entire year goes into insurance. In the US that’s almost 2 trillion dollars every year that goes straight to pay for these sorts of things and sits there until it’s needed.