I would be happy to see normal mail service drop to 4 days a week
Mon, Wed, Fri, Sat (Sat primarily for signed deliveries for people who were not home during the week)
The USPS delivers about 2/3 of the stuff I order from Amazon these days. So I wonder about this one.
Mail should be delivered 3 times per week for residences. Would save almost 50% on vehicle expenses and 50% on Labor to deliver.