It is not the airliner which is the problem, it is the government. Compare it with the tobaco and alcohol industry: You can’t expect them to protect the health of their customers and to reduce their profit voluntarily, If you want to reduce alcohol consumption, you just need to make the stuff more expensive with taxes etc. A bottle of spirit would cost the same as a bottle of cola if the government would not interfere, it is the task of the government to avoid this danger to society. The same with air travel: To make air travel less attractive is not the task of the airliner but a task of the government. At this moment, airliners are pampered, get tax free fuel, can expand at the cost of the neighborhood, etc. so what do you expect?
The air travel industry doesn’t care much about fuel consumption. They still descent with flaps and spoilers out, instead of trading off altitude for speed slowly. They fly with speeds of 400+kts, but just like with cars, going slower saves fuel. And as long as the airliners demand fast airplanes, manufacturers keep designing them, despite the higher fuel costs compared to a slower plane. Again, making fuel much more expensive could cause the industry to rethink their strategy. There is a tipping point where customers accept a longer flight time for a substantial reduce in costs.
I think even in the US there is more tax on your car’s fuel than on the airplane fuel. And I’m pretty sure there is some special tax on whiskey and other concentrated spirits, and tobacco, etc. Even in the US tax is used to direct social behavior.