The USPS is part of the federal government despite the phony claims that it is independent. The federal government including the USPS has large levels of retiree health care. I doubt that any retiree health care payments matter because there is no portfolio to support retiree health care. The USPS is not being used to subsidize other areas of the government. The opposite is true. The USPS has been provided recurring subsidies. The USPS is engaged in a misinformation campaign to dump its unfunded pension liability on other areas of the government.
I've computed out all of my deposits over the years, allocated interest to them using the current T-bill rates at the time, and gone ahead and retired.
Based on my current "draw" (to use a non-government term), I would need to live to 200 years of age to actually recover my deposits with interest.
What you "schmart guys" forget is that federal retirement is not inheritable. The payments end when the beneficiary dies. That tends to gobble up all that "unfunded pension liability". Actually, it doesn't just "tend" it actually does gobble it up.
Only in the private sector can you compute out a personal retirement program that assumes heirs will get a piece of the action. Rockefeller had such a program. Old Joe Kennedy had one. I'm sure most rich folks do. Salaried personnel usually don't except for their 401(k) plans or IRAs.