And unlike in trad fi, you can have the dispute mediator / escrow manager / trustee be physically limited in what they can do with the money.

Visa can run away with your unclaimed payouts (if forced to do so by law enforcement for example). This doesn't have to be true in crypto; you can set things up so that the third party can either release the money to the payee or send it back to the payer, without giving them the capability to send it to some arbitrary address of their choosing.