Easy, you stay in the air by accelerating air downwards. Physically, you make sure to collide more with air molecules from below than from above. It's called angle of attack and you can experiment with it by sticking your flat hand out of a car window.
In helicopters it's easy to see, in planes people get all magical about it.
Well they can't, not by the same mechanism. They can in the same way a wingless missile would, which doesn't generate lift it just turns itself through air.
I think it's far from useless... Because it helps to focus on what could possibly be happening. It's not "true enough for an 8 year old's purposes", it is the actual truth.
The air is being accelerated downwards by the airplane. Newton's third law. To stay aloft, the airplane has to manufacture a counteracting force to gravity. And the only way to do that is by accelerating something downwards.
So, we can discuss whether or not the curvature of the airfoil matters, or the angle of attack matters, but the simple fact is that a lot of air has to be accelerated downwards somehow for the plane to stay up.
And the more magical descriptions of lift, including the broken Bernoulli airfoil model that was accepted for so long, are easy to discount once you focus on this important fact.
The wing is curved to force air downward without the clumsy ruddering effect described in top level comment. That downward force is the newtons law lift. If you go too fast you lose the smooth flow over the wing and you lose lift. Too slow and you don't force enough down to generate enough lift.
I don't know what it is with people not accepting fluid dynamics. We can simulate wing performance just fine but they want clean formulas and physics just does not oblige. Seems like a them problem, not a physics problem.
In helicopters it's easy to see, in planes people get all magical about it.