"most americans" absolutely do not have "an order arriving every other day".
I order amazon on average once every 3 weeks. My mother (who has full time career and is under 60 years old) has never used amazon. Other members of my family also seem to rarely use amazon.
Also, having an order arriving every other day is incredibly wasteful.
No it's not. There's an Amazon truck on my street every day. Adding one more package to that truck costs ~nothing. That's why free shipping is free.