And the pitch of the wing causes one side of the wing to be hit harder by air molecules than the other, just like GP said. Maybe you hit reply on the wrong post?
The 'air molecules impinging on the airfoil' theory of lift is not wrong, but does not account for a large fraction of the lift generated either. In a dense enough medium such as air at normal flight altitudes, you have to take into account how those air molecules interact with other air molecules and not only the airfoil. Sum up all those interactions, and you get fluid dynamics rather than a molecule hitting a surface in vacuum.
Better for what? Fluid dynamics is actually great for a huge number of stations. For pure realism you can use Quantum Mechanics, but good luck simulating that for a protean let alone a 747.
My point was you can still find a lot real world issues for example wing icing. So, that you need to be aware of what you are and are not simulating.
