They do have insurance, if you look at the budget breakdown it's a component of annual dues, just taking OKW as an example, here's an old article breaking down what goes into dues.
https://*******.com/dvc-information/financial/dvc-resort-budgets/resort-budget-for-okw/
It's not perfect, but look how much more the insurance for VB is (4x!)
https://*******.com/dvc-information/financial/dvc-resort-budgets/resort-budget-for-vb/
I can't post documents behind the membership wall, but if you log into our DVC account you can read the condo annual meeting notices and they go into more detail.
If insurance wouldn't cover something, there's a capital fund that would then have to be replenished by later dues. There were some recent (ish) FL laws regarding insurance that I believe increased dues (or were blamed for increasing dues) to increase this fund, though I'll have to rely on someone more knowledgeable to chime in more.
Few years back, when we owned points at HH, we had to pay an assessment to cover hurricane damage. Wasn't too crazy but extra cost on top of normal annual dues.