You have trillions of dollars worth of military equipment from the cold war mothballed or in storage.
Most of it will never see use because it's outdated technology. There are thousands of planes, tanks and miscellaneous vehicles just sitting out in the desert waiting to be scrapped or reactivated.

We have billions of dollars of military equipment that was made 10+ years ago and has been sitting around since then because we have no reason to use any of it.

To the point where military commanders are begging Congress to not make the military budget so big because it's being wasted on building more assets that aren't seeing any use.