Planes always have been and always will be, a part of FH game play. I can to some extent agree that the interaction between player in plane and player on ground is somewhat one-dimensional, but we do throw everything we have at the ground forces to be able to defend themselves.
What we lack is elements of overtaking airfields and denying the other team their air forces, only Cobra afaik offers this (and even there you arent denying, only moving the enemy air force)
I also think that air-to-air battles end a bit prematurely, longer duration dogfights should make it more fun. And ofcourse, some clear objective for players in planes is needed, apart from just randomly flying around in a little box and randomly spam rockets or bombs to the left and right.
Planes arent designed bad, handling and maneuverbility has increased a lot the last year. they just lack a clear target experience. They're flying tanks, more or less.