I am already surprised it is possible to draw good airfoils with paint.

No offense here but paint comes FREE with windows and I am not sure it could draw a wing skin with all the rivet holes pre-punched so that when the wing is assembled, you already have the 3 degrees washout built in the wing. No jigs, no stress to the wing, it is built with the washout. The wing has 13 DIFFERENT wing ribs with 12 DIFFERENT nose ribs and every hole lines-up the first time we try it.

I am not saying that it could make me a better designer as I do not "see" how an airplane will fly before actually flying it so I may have to guess much more to get things right.