That’s not how “efficient” works. Not only do you look at each person individually instead of the whole system, in which everyone having their whole transport is ridiculously inefficient in required space, energy and coordination effort alone, it’s also likely to actually be so incredibly inefficient on the whole system that the value breaks down for each individual person, even if you completely overlook the drastic side effects on the whole system, by not actually getting anybody anywhere in a timely manner.

Thinking like this baffles me, I can only hope that you are very young.