If your lean and nimble business can outcompete the sclerotic and wasteful government, go ahead. No one will be happier than the public and the tax man. If not, then people will get their services from the public option.
You can use Fedex, UPS etc to ship anything from anywhere to anywhere. Nothing is stopping you from using fedex to ship your christmas cards as well. I assume people stick with USPS for simple letters because its cheaper and easier, not because of any enforced monopoly.
The USPS was created in 1971, which is not the 18th Century.
(Heck, even the monopoly rules that originally applied to the Post Office that now apply to the Postal Service were first established in the 19th, not 18th, century.)
There’s a monopoly on residential letters, and a monopoly on mailbox access:
https://en.wikipedia.org/wiki/United_States_Postal_Service#U...
> You can use Fedex, UPS etc to ship anything from anywhere to anywhere.
You actually can’t, there are very specific rules for what you can use a non-postal carrier to send to which addresses and at which prices. Which is why you don’t see general, non-express, or cheap letter delivery from third-party services.
Credit serves lots of useful functions in the economy, and has done since ancient times[1]. Consider someone (say a farmer) who needs to make investments (seed, fertilizer, equipment etc) that will pay off in the future (when the crop is harvested and sold). It would be very much harder for them to run their business if they could not borrow, or forward sell their produce (which is an agreement that requires credit as a basis).
Or consider a merchant who needs to import or export goods. While the ship is at sea, either the buyer or seller almost certainly requires credit.
Think about very large assets (eg houses). Most people who buy property require a loan. To buy a house for cash where I live would require a literal lifetime of saving - where would you live in the meantime? You would need to rent. How would your landlord be able to buy a property if they could not borrow? If you did eliminate borrowing to purchase property literally only the ultra-rich would own property and they would own all the property. This would enforce an extreme unfairness that would be self-perpetuating as it would be practically impossible to transition from the renting to the owning class. This is similar to Europe in the early medieval period when hereditary landed gentry owned all the property and as a result the vast majority of people lived lives of abject poverty.
In general if credit did not exist, economic activity as a whole would be severely curtailed.
Do people use or extend credit unwisely? of course they do. Should it be done away with? Probably not, or not without understanding the profound implications this would have across the economy.
[1] https://erenow.net/ancient/money-in-classical-antiquity/6.ph...
Because people need a place to live, it would be helpful if you stated which alternatives you have in mind?
Renting for the rest of your life? Building a house, paycheck to paycheck? Something more radical, like abolishing private housing and give every citizen a place to live, for free?