This is probably a big reason why things are slower now.
Quote
Today more than 95 % of First-Class Mail and more than 95% of First-Class packages are moved through our ground transportation system. This is a reduction by over 90% from just two years ago and puts us on course to reduce approximately 1 billion dollars from our annual air transportation cost.
So the postal service, like everyone else out there, is finding ways to cut costs. Do you think UPS Amazon or FEDEX would be better delivering a letter? How many would pay 2x or 3x the 1st class cost if they took over? Seems some think a letter should "move" as fast as an email these days.