Grocery delivery is done with trucks fully loaded with orders and an optimized route for fuel efficiency.
It is actually much more energy efficient to package 40 ppl grocery orders in _one_ 4.3 tonne 10' truck, and make an efficient delivery route, than to have 40 people drive to their grocery store in an empty 3 tonne vehicle.
I am not sure what the situation in the US is but realistically in Europe if you have a big enough family online grocery shopping is a no-brainer.
I only shop physically for very specific perishables like bread, fruit, cheeses. Have been doing it every since our family grew and our time, mental bandwith, and lower backs decayed.