They suppose both parties have equal power (money, ability to analyze the smart contract). I doubt most contract negotiations are like that. Signing a smart contract with Google, written by Google engineers, is like signing your own death warrant. You'd have to hire your own E&Y consultants to verify the contract doesn't screw you, and then we're back to the problems of regular contracts.

Perhaps useful in 1% of contracts, useless otherwise.

can you give some examples of them being legitimately useful and advantageous compared to the existing financial infrastructure?

haven’t seen anything where it’s actually needed or better. and basically all examples end up with some sort of trust needed at some point.

such as gambling on the outcome of a sports game. it would still require a dependency on some sort of Api to provide the sports results and then you’re trusting the api to give uncorrupted correct results… which defeats the purpose of “trustless”

You are thinking way too extreme. An API is still a hell of a lot better than a sketchy bookie. I would trust the former and not the latter. Which helps break up the centralization of betting because it is much easier to establish trust in a 3rd party source of truth than it is to establish trust in someone being financially responsible / honorable.

Will it improve the established market providers for sports betting? No. But that's the point. It enables people to make a small business betting shop

Decentralized insurance pools allow anyone in the world to tap into that liquidity. Allowing farmers and businesses in developing countries to get stability they've never been able to buy before.

Futures contracts so they can easily sell their products at a good price regardless of market fluctuations, transfers the risk to the investors.

Smart contracts are still in super early days, the first foundational building blocks are being laid. Soon many more things will be possible.