Proactively sabotaging something and then using the consequences of the sabotage as evidence that it should be dismantled isn't "it either works or it doesn't". Such details actually matter.
Incompetently legislating some thing to ruin isn't a failure of the thing, it's a failure of the people writing the legislation.
Requiring that benefits are accounted for is not 'sabotage', it's actually sound and transparent financial accounting.
Such details actually matter!
If, after the real cost of operating USPS is exposed and they cannot cover it with revenues - or - cannot be subsidised enough - then the US can make a more rational decision as to whether or not it should exist.
That's a model not based on reality but on theory exercises with a set of axioms that get handpicked to support an a priori assumption, regardless of reality or evidence.
People on purely ideological grounds killed off, for instance, the USPS savings system, which was a profitable banking arm.
It took 20 years, for instance, of foot dragging after the stamp was tied to inflation to keep it good forever and not lose value. That was part of the original bill but killed off to make things more broken by people who run on "government is broken"... Yes, you're the one breaking it.
People on pure fundamentalist ideology grounds have aggressively redefined the post office to force it to be unprofitable. The free market fundies have been yelling the "Communist" cry about usps since the 1950s, stabbing it at every opportunity.
It's also not a fair analysis because fedex and ups get subsidies, tax breaks, and other kinds of assistance on the million dollar scale all the time, many times a year. They aren't free agents in the slightest. And unlike usps, they aren't being administered by people who want them to crash and explode.
Many other industrial countries can do this at profit (Canada for instance), but of course, we are told we can't look at that either. It's such crazy time eating nonsense. They bark back that we dare ruffle the robes of the high priestess...pearl clutching is what they turn to.
"We could fix it but then we wouldn't show how broken government is .. durr durr" knock it off already.
These ideological fundies are con artists, a 21st century version of a street hustler who hide behind optics and theater. It's a huge criminal violation of the public trust
The very nature of the USPS, that requires massive government support just as mail usage fallen by 50% in the last 15 years, that few people use it for material purposes, that it continues to have massive unfunded pension liabilities - is ideological.
That is should exist, or be 'owned by the government' is ideological.
You haven't provided any evidence for your cynical argument: Using FedEx and UPS examples abnegates your argument because although they do receive subsidies here and there, it's nowhere near the magnitude of USPS. If the USPS were to need only that level of assistance, few would be concerned.
Regular mail is an antiquated service that has considerably less value in the 2000's - it's a dying business and should naturally shrink to a tiny fraction of its previous use. Almost every bit of paper in the mail today is a waste, there's hardly a need for it.
The Royal Mail [1] has been privatized and it's doing mostly fine. Not perfect, but arguably better than before.
The fact it works well enough, informs us that those who believe mail must be public, archaic and highly subsidized are the ideologues.
Personally, I don't care, but I also do not see gigantic public entities being able to adapt to major changes in market conditions.
What America needs more than a debate over public or private is considerably better regulation in banking, finance, consumer goods etc..
Incompetently legislating some thing to ruin isn't a failure of the thing, it's a failure of the people writing the legislation.