Why? I like the ability to move around. Bicycles are not practical in many major US markets.

51% of car trips in the US are less than 6 miles long. Maybe reconsider if you need a multi ton vehicle with 300 mile range to get a loaf of bread.

https://afdc.energy.gov/data/10318

How will I buy my immense packages of processed food from Costco though?

With one of these

https://www.costco.ca/wike-premium-suspension-bike-trailer--...

If you're getting long lasting bulk packages then you're being energy-efficient despite the large vehicle.

You're correct, bikes are not practical. That's step one of analyis. Now we have to ask why bikes are not practical.

It's because everything is really far and we design our cities to burn as much land as humanly possible.

One side effect of that is that bikes are inconvenient. Another is that nobody can afford housing and starving homeless people are harassing you for money.