(I have a vague idea that this may be a politically loaded question, so I just want to put this disclaimer here to say that I genuinely don't mean for it to be. I don't know much about the past of the USPS and why it is the way it is, so i'm asking)
I think it's less a philosophical question -- is mail like roads or police? -- vs a matter of efficiency. It's obviously possible to NOT lose money delivering much more difficult things than paper. FedEx and UPS do it all the time. But they're private businesses who compete with each other (and Amazon and whoever else), so they have to figure it out or they won't be around.
The USPS, meanwhile, doesn't have to compete with anyone (in fact, it's illegal for anyone else to deliver mail) and has no incentive or need to be efficient because they can draw on the US Treasury whenever they need to. It's not that they're bad people, it's just the nature of the incentives and system involved (and also it's run by congress). These same dynamic would be there in banking though, which is why this seems like such a bad idea.
Do you make people hard to deliver to have to pay more, or do you "average" out the cost and make everyone pay roughly the same amount?
With a combination of taxes, flat-rate fees, and delivery-distance based costs, I think it's more than possible to make a system where it's not "free" or extremely cheap to send somewhere hard-to-get, but it's also not prohibitively expensive.
And IMO the postal service is riding that line in a way that i'm happy with. I appreciate that I can send a small box across the country for $5, and I can do that whether I live in NYC or in middle-of-nowhere pennsylvania. And I'm more than happy to pay a bit more in taxes to make up for the difference that the flat-rate doesn't cover if it means that lower-income individuals won't need to pay as much to send mail at all.
I know that there are problems with not having competition, but I think mail delivery is along the same lines as other "naturally monopolistic" things like power, water, sewer, etc...
Yes, "state sanctioned monopolies" can be a problem, and they have their downsides, but I believe for natural monopolies they are the best solution.
They also do not have the requirements to serve the entire country, and they do not have the bonkers pension requirements placed on them like the USPS does.
"The USPS, meanwhile, doesn't have to compete with anyone (in fact, it's illegal for anyone else to deliver mail) and has no incentive or need to be efficient because they can draw on the US Treasury whenever they need to. It's not that they're bad people, it's just the nature of the incentives and system involved (and also it's run by congress). These same dynamic would be there in banking though, which is why this seems like such a bad idea."
Money is far from being the sole motivator.
Because it's obviously a service of value, and profitability is what tells you that the net value created is positive. If you're spending more on delivering mail than people are willing to pay, you're squandering resources that could be better put to other uses.
> Why isn't mail (and possibly other services that the USPS could provide) treated like road maintenance or police or whatever else?
It should be; all of these are also services that have value, and should be held to the standard of profitability to ensure that the net value created is positive.
You've just guaranteed that no roads would ever be worked on in poor residential areas.
Why not? I said net value created. That doesn't mean each individual road has to show a profit. It means the enterprise as a whole has to show a profit. If improving roads to poor residential areas gives those people more options so they can create wealth and not be poor any more, that's a profit.