Can't speak to the others but insurance couldn't really work that way and compete on price with traditional insurers. The only way for the "policyholder" to be

Can't speak to the others but insurance couldn't really work that way and compete on price with traditional insurers. The only way for the "policyholder" to be confident that an untrusted "insurer" will have the money to pay their claim is if the smart contract forces the "insurer" to fully collateralize it - e.g., to fund a trust or escrow account with the maximum amount of money that it could possibly be required to pay out in claims. For insurance to be attractive as a seller, you need to pool enough risks that you can generally hold a reserve that's much lower than the maximum possible loss amount because otherwise you need too much capital to fund it. You can get around this to some extent with reinsurance, but that's not eliminating risk pooling, it's just shifting it to a different balance sheet.