The A-10 is not really a 40 year old aircraft, most of those flying are barely older than 30 years, with brand new wings, giving them very long lives if the politicians would let them fly.
My limited experience in defense contracting is that politics and cronyism count for a lot. Sometimes technical capability and cost are lower on the decision scale.
If you take a close look at the tactical aircraft world you will discover that the AF, in that operational arena, is based on a 15-year replacement cycle, the 1991 cycle didn’t happen because of the “peace dividend”.
The problem with the A-10 is nearly 40 years old and doesn’t look like a proper AF fighter. Image is all important.
How does the Army view the A-10? Those in the dust and dirt love it. But, then it represents the air power that keeps them alive.
BTW - the shortest serving AF Chief of Staff, Michael J. Dugan - 78 days, lost his job, in part, when he tried to convince Gen Norman Schwarzkopf that the AF was only going to offer F-16s in the CAS role instead of the A-10s that Schwarzkopf wanted.
Second BTW - this will be the third time that the AF has tired to use the A-10 as a funding source for a “modern” fighter program.
It's not about what is best for the military - it is about the best deal for the politicians and their financial backers.
The sweetheart contracts, pay-offs, under-the-table money and kickbacks will be much bigger on an entirely new weapons system.
How old are most B52’s?
But they have been retrofitted and can continue to fly forever
Warthogs are great at doing away with tanks and ground troop protection or decimation.