As a first-order approximation, yes they're both zero sum in expectation. The amount lost is approximately the amount won in the long run, ignoring casino and insurance company expected profits.

At least that's true for for-profit insurance. When governments get involved, the line may blur between insurance and welfare, making it less zero sum.

The insureds are the only ones bringing money to the table, the insurers take a cut, someone loses and someone wins.