Or maybe we accept that the postal service was important enough to include in the constitution, [1] stop demanding an important government service pay for itself, and just give USPS tax funding to make up any shortfall.
Lets also not forget that UPS and FexEx often use USPS for the last mile of their shipments. [2]
[1] https://en.wikipedia.org/wiki/Postal_Clause
[2] https://www.wsj.com/articles/u-s-mail-does-the-trick-for-fed...