It seems like you don’t understand how fuel economy works. Aviation is more fuel efficient no matter how you slice it and has been since the start of the millennium.

If your premise is that 52mpg/1 passenger = x mpg/3 passengers means that x is 104mpg/passenger then that means that 67mpg/1 passenger for a flight of 100 people is 6700mpg/passenger. You can’t divide for one and multiply for the other.

Also, planes get more fuel efficient the longer the trip because the majority of their fuel burn is on takeoff. Once they’re in the air, their fuel use is minimal and they lose the weight of the fuel as they continue which further makes it more efficient.

So no…your point is not clearer because air travel is more efficient than travel by auto in all cases except, again, the shortest distance travel where it’s not even practical to fly. You can try to limit your data to only trips with more than 3 people (the point where driving becomes more fuel efficient) and only for long distances but that means you’re only further scaling down the impact that making efficiencies has since that’s not really the most prevalent use for cars.