I remember years ago around the Holidays here in NYC, we used to get mail delivered as much as 3-4 times during the day 6 days a week.
First class postage was 3 cents. Now it is 14 times as much and service continues to slowly deteriorate.

The post office has lost a lot of business to both UPS and Fedex not to mention the Internet. Why not raise the postage on junk mail not first class and try to regain some of that lost business.
It seems to me the P.O. is following big business in cutting service and raising prices