A better explanation of lift of an airfoil

-Air never leaves the flat bottom, hence it always gets pushed upward, known as lift.
-Drag is air pushing upon the leading edge, bending around it.
-The key is the lack of air on top to apply down pressure.

The reason is that the airfoil traveling above a certain speed causes the following:
-After being displaced by the leading edge air doesn't travel back down to the top surface faster than the top surface tapers downward. Therefore it is unable to apply pressure. It's that simple.

I've heard explanations saying low pressure on top due to higher velocity that is due to farther distance to travel. While those conditions might be true, that does not properly explain the phenomenon.

Airfoils depend on air pressure, going through unpressurized air wouldn't yield any lift (if you could somehow get unpressurized air to stay put that is.)