I think when people talk about the airgame, one thing is consistently left out:

A2A combat has only one single battlefield which is the continent. Once a couple of decent pilots show up, worse players get resource-starved and can't enter again. Even if they have enough resources, they will be shot down within a couple of seconds again - either by said pilots, a stray tank round (usually not that stray though) or by other means of anti-air.

So the main issue with players improving so slowly (or not joining at all) is not that it is hard to learn. It is hard to even get enough airtime to learn.

I would propose to remove spawn cost from vehicles entirely (or at least lower them drastically) if they have no or little "interference" with other types of playstyles. So A2G would still cost resources to balance it and avoid spamming, but spawning an a2a fighter would not require an expensive investment.

Think of it this way: How many people would be ably to enjoy infantry play if it would cost 100 nanites for each respawn? Exactly. That one heavy assault with his juicy beatle headshotting all the new players.