You know why Congress will never kill the post office? Two words: FRANKING PRIVILEGE.
Incumbent Congressmen do not have to pay for any mail, including those "Constituent Update" newsletters that show up around re-election time. This is one of the major benefits they have, and gives an incumbent a decided edge over a challenger in terms of spending money for mass mailings.
Ben Franklin is probably spinning in his grave to see what his beloved Postal Service has become.
My suggestion?
Give FedEx and UPS and maybe DHL a chance to competitive bid for the whole shooting match. Regularly scheduled delivery, with suggestions for a possibly reduced delivery week. Give customers a chance to opt out of third class and other mass mailings like catalogs and flyers and other commercial crap.
Tell them all current USPS employees have to stay on for a six month evaluation period. Those who cannot step it up and provide timely customer service with even a basic sense of competency are GONE. Either they add value, reduce customer wait times at post offices, and get the mail delivered on time, or they are DONE. I think that will separate the wheat from the chaff and prevent massive amounts of retraining. Some postal employees are hard working decent people who are stuck in a quagmire of an operation and would probably appreciate a chance to work for a private outfit with better pay and benefits. AND NO UNION.