Anyone who says masks are ineffective at some level of protection vs airborne transmission is just plain stupid. However the effectiveness does vary from material and proper fitting, anything that provides a block between whats in the air and your face provides protection. Even having fly screen over your face will afford some minute protection but it's not worth the effort, ie you will probably still catch covid as it will not stop enough of it. It all comes down to how much you are exposed to, vs how much is caught in the material vs how much your immune system can handle.
That being said most airports are large, well ventilated spaces, as long as you can maintain physical separation from others there is no need for masks. On board an aircraft it's probably pointless, as you are sitting in a poorly ventilated tube where you are surrounded by whatever is expelled from other passengers, it would really come down to whether you were seated near to a covid + or not. The masks would only be of benefit to say, passing through security, where you are confined in close proximity to others, but moving constantly through the area in short time, or on a transit bus etc. The obvious protection comes from a C+ individual coughing, the mask will slow down and catch a lot of the ejected particulate, reducing both the amount of virus ejected and the distance in which it's ejected to. That's assuming the wearer doesn't take off their mask to cough, which I've seen on numerous occasions.