All the statistics I’ve seen place US internet usage at between 70-80% of the population. Get back to me when internet usage approaches 99% of the US population, and I’ll consider eliminating the US postal service. Until then, it’s a non-starter for me.
Now, as for changing the number of days mail is delivered, I’m amenable to that, but I’d rather have the non-delivery days broken up rather than together, as suggested above.