Why are you fixated on the lowest tier of "zero-trust", that is eskrow? And why does the number of people using a service or technology have to match what Paypal clears to be an improvement on the status quo? At the end of the day, we were talking about the concept of trust, and it seems pretty straight forward to me that lowering the number of parties involved in a transaction reduces the number of parties that need to be trusted.

Paypal doesn't even appear on the radar (even if you overlook their outright predatory and scummy behaviour) when there is the option to outright remove the payment provider from the equation and reduce the number of involved parties by one, while still allowing for a third-party (a human for eskrow, or an oracle with human fallback for a smart contract) to arbitrate if necessary if one or both parties are malicious.

Also who says there is no legal action if it goes wrong? It's better to set things up such that things can't go wrong, but if they do, the rule of law doesn't cease to exist just because it happened online.

I haven't seen a coherent argument yet, but maybe I'm missing something...