I know this is the political line of the day, but the reality is USPS is, has been, and will be insanely inefficient for decades. Decades. That spans multiple presidents from both parties. Decades.
The very fact that USPS receives funding by Tax Payers, but also still charges the same tax payers money to use services, and still manages to lose billions of dollars every year is a modern marvel all in it's own right.
The very fact it costs USPS more than $0.55 to deliver a letter to your mailbox (which only USPS is legally allowed to put mail into for whatever reason in 2020), is insane. Raise rates they'll say! To what end? To the point where UPS or FedEX rates start looking attractive for normal letter mail? What will happen then to the USPS?
For larger packages over a few pounds, it's already insanely cheaper to ship packages via UPS or FedEx. Sometimes over half the price in difference. Neither UPS nor FedEx are subsidized by Tax Payers + Still Charge for Services. Somehow, they make a profit and deliver packages on time.
The mismanagement of USPS is as criminal as it is resolute. It is not the current administration's doing - claiming so is not just intellectually dishonest, it's flatly wrong. No, the mismanagement of USPS has always been, and all signs seem to say it will always be.
EDIT: It's a myth that USPS isn't tax payer funded. Pay attention to the wording they use - "Not Tax Payer Funded". That says nothing about routine bailouts[1][2][3], which are so routine they might as well be scheduled. How is a bailout not tax payer funding? Run yourself into the ground then get bailed out by tax payers again, and again, and again, and again. It would probably be more efficient to actually just give them the money up front.
[1] https://justthenews.com/government/congress/congressman-says...
[2] https://keller.house.gov/media/in-the-news/usps-has-lost-78-...