I know that I am chasing a rabbit down a different hole, so I will start with USPS.
With the USPS you get what you pay for. Regardless of how the department reached the point it now occupies, you get what you pay for and what it is. USPS is not designed to be fast or customer friendly. They move items from point A to point B within a structured and inflexible system. Their current customer base, bulk mailers and last mile for UPS and FedEx, are utilizing what USPS has morphed to.
USPS is suffering from an all-too-common illness within our society. I can't remember the technical name, but it is when you are given a directive to do something, so you agree to comply and in doing so you go overboard. It reared its ugly head with school libraries. When told control access to certain literature for appropriateness, librarians said "Sure, I'll do that" and then they removed all the literature from the shelves and screamed "book bans" and "censorship." The directive was to say what is valuable information for high school students isn't for the consumption of fifth graders.
In that mindset, the USPS has been told "no overtime," so they limited to eight-hour days. However, instead of stagering shifts they went full 8 - 5 for everyone. They complied with the directive.
Another common issue in government, and many presidents have pulled their hair out over it. Now Musk is trying to make a dent in it in his brief four month term. "I have a budget of one million dollars, so I must use it." A department does their job under budget, but under fear of losing budget money for next year the over purchase supplies, do make work jobs, anything that will burn the surplus. Workers do "make work jobs" to justify their position. This is part of making systems and programs far more complex than necessary. They create multiple levels of repetition, or spread the work out over four clerks rather than one stop, to create positions and fulfill promises and give paybacks.
Guess what. In ranting over what I see in USPS I just explained and justified what Musk is advising and implementing for Pres. Trump. It is what every company does when they merge, purchase, change leadership, or just hold an internal audit on operations.