A brofist to TrashMan for a eloquently post
Suspension of disbelief is very important in a game and omitting details are no help to that.
Details that enforce this are scrapped and more, are seen as the enemy of gameplay fluidity in nowadays games.
Losing an airplane should be a big deal and just having it in the hangar after being destroyed by a UFO feels like cheating.
I could live with conventional ammo for weapons and aircraft but never with the nonconventinal that requires advanced techniques for manufacturing and scarce alien materials.
If the game economy is balanced properly, anything is possible.