Ignoring EVs for a moment, a Toyota Camry hybrid, which can carry five people in more comfort and carrying more luggage than a light aircraft, gets 50mpg on the highway.
22 mpg is not terrible only if your frame of reference is pickup trucks, whose load-carrying capabilities can only be matched by far larger aircraft with far higher fuel usage.
Furthermore, aircraft that cruise at 250 knots are not going to get anywhere near 22mpg. A Lancair Evolution, a reasonably modern four-seater turboprop that cruises at around that speed gets something approximating 7 mpg.
A Toyota Camry hybrid does not move 110mph at 22mpg with a 700mi range. Once you start moving fast the fact that it's a hybrid is irrelevant since the engine must provide 100% of the power.
I personally don't see the point of comparing a car at 50mph with a small plane at 120mph, but if you really want to, I bet that easily doubles fuel efficiency. No one flies at Vg because that's stupid, but you COULD, and then you're basically the same fuel efficiency as a car but flying in a straight line.
Even that 22mpg is not a 1:1 comparison because of that inconvenient "as the crow flies" thing. We can build more efficient aircraft in theory, but in practice the regulation gets too expensive.
Turboprop airplanes will be less efficient than pistons in general (though few pistons can hit 250 knots). A Lancair IV-P is a better comparison aircraft, hitting 335 mph at 75% power, 17.5gph, for a net of 19mpg at considerably over 250 knots.
On the other hand here is a Long-EZ that gets 40 mpg flying at over 250 mph (so not quite 250 knots but still). The actual savings will be higher since one can fly in a straight line most of the time. It also avoids congestion and ... is simply more fun than driving. Also an auto-pilot in aircraft has been a real thing for quite some time while same in a car ... is still quite pathetic. I have eaten plenty of lunches comfortably while flying a plane while I would not be comfortable doing it while driving.
That’s impressive but it hardly sounds like a comfortable experience for passengers, and while I get the whole argument that overregulation has made light aircraft less safe, i wouldn’t get in that plane thanks.
22 mpg is not terrible only if your frame of reference is pickup trucks, whose load-carrying capabilities can only be matched by far larger aircraft with far higher fuel usage.
Furthermore, aircraft that cruise at 250 knots are not going to get anywhere near 22mpg. A Lancair Evolution, a reasonably modern four-seater turboprop that cruises at around that speed gets something approximating 7 mpg.