It's not scientific at all, but for most people gas mileage comes down to "how often do I have to go to the gas station".

Which is why once electric cars passed a certain point they become effectively infinite mileage as far as people are concerned (as they never have to think about charging as it's always charged overnight).

Similar for how for most people there are only two speeds of computers - I have to wait for it vs I don't have to wait for it.