The legal system still exists though, and people can still be forced to do things. That leaves the non-automatable work to humans and takes away the automatable things rather than forcing everything through humans to manage edge cases where you need them.

For my will I literally enter into a form what I want to happen, but then when I die it'll be down to another human to go through it and manually carry out my instructions.

Chargebacks can be opt-in and escrow is a tutorial for smart contracts. I don't need chargebacks on a cup of coffee, and I've been unable to make a payment due to high chargeback risk - despite me being entirely willing to take on the risk of non-fulfillment.