Idk, I think that a USPS run like a business would either just decide not to operate in the less population dense parts of the US or charge them exorbitant rates for service. Even as someone who lives in a dense urban area, I think it's generally a good idea to have guaranteed mail service to anyone in the country even if that means that I'll essentially be subsidizing the cost of delivering mail to rural areas. I have trouble believing that USPS could be profitable, affordable to everyone, and available to everyone, and I'm much more willing to sacrifice the first one than either of the other two.