"but payments at the post office are forbidden in the United States."
The Postal Service
does have some limits, since it was created as a monopoly it isn't allowed to outcompete everyone at everything.
But actually, you can use the postal service
for payments. Send an empty matchbook (matches would be hazmat<G>) by USPS COD for a thousand dollars. The recipient has to fork over that thousand dollars before delivery
will be made. And once it is forked over? Yup, payment irrevocably made to the sender.
I have no idea how big their limits are, but within their limits, USPS COD is considered a very effective payment option. As are postal money
orders, which are accepted as cash.
All of which comes back to, there are many ways of transferring "value". Very few folks are willing to patronize all of them, and if you want to buy something, the bottom line is that you have to work within the seller's terms. Which is why some sellers get rich while others go broke, too.
The banks would prefer not to handle checks, because the damned things are expensive. In the US, the Federal Reserve System clears all the checks, overnight, at each FR district. That's how Fedex (the shipping
company) got started, with a contract from the FR to have all the checks airfreighted "same night" from each district into and out of the others, so they could physically be cleared each night. Which ties into why checks from different distrcits have different float (clearing) times, and why the laws eventually changed so that now they can process images
, instead of shipping
paper checks around. It just costs too much to move paper around, compared to data. And if the FR system can't READ a paper check? Last I heard, they charged the bank something like $3 to manually process it, if the check's magnetic charactes couldn't be read. That was years ago.
Checks, EFTs, paper money...I'd rather be paid in livestock. Two chickens and a goat, keep your filthy government