Actually, the Postal Service has been intentionally disrupting its own service since at least the Nixon era…… Back in 1764, colonial Postmaster General Benjamin Franklin proclaimed a goal of two-day mail delivery between New York and Philadelphia. In 1989, the Postal Service ratcheted down its goals, labeling as a success two-day delivery from New York City to nextdoor Westchester County, N.Y.
https://www.aier.org/article/mail-slowdowns-started-50-years-before-trump/