It's also to maintain the capability. You need to keep people continuously employed in that area or else you run a high risk of losing the ability to field new aircraft.
It is not so different from subsidising farming (similar pros and cons) to ensure food security.
There is a lot going on in the supply chain that you need to maintain at a baseline level if you ever expect to have to fight.
From a very macro level whatever airframes get shipped may matter less than maintaining all the specialised knowledge and suppliers that you need to produce them. "Looking after the machine that makes the machine".
It is not so different from subsidising farming (similar pros and cons) to ensure food security.
There is a lot going on in the supply chain that you need to maintain at a baseline level if you ever expect to have to fight.
From a very macro level whatever airframes get shipped may matter less than maintaining all the specialised knowledge and suppliers that you need to produce them. "Looking after the machine that makes the machine".