As I understand it, F-117 maintenance is a major PITA.... Probably one of the reasons why they're being retired.
Also, look at the missions they're designed to fly. I think it's likely that they've been replaced by unmanned vehicles, and the B-2/F-22 mix.
***The F-117s are *only* 25 years old and are being retired.***
I suppose that depends upon what you mean. The technology was all developed early 70’s. It had only limited RAM technology and very limited offensive capability. The Lightning II is truly a stealth fighter/ bomber. And, the technology for replacing the F-35 is already under testing ,plus, I believe that the F-45 ~ I think that is the proper designation for the UCAD ~ is getting ready to enter production phase....
As far as the comment re the Nighthawk that was shot down (another poster), even though presumably the Russians now have the remains of the aircraft, they may have the materials of the RAM, but they don’t necessairly have manufacturing capability, which is STILL top secret. But, they do claim to have the ability to artifically create a plasma envelope for their fighters, which can be retrofitted to existing planes. It would, if true, render their planes even more invisible than our best stealth technology.
This plane is being retired because her time has come, just like the time has come for the F-15 & F-16, both comparable time weapons.
... and the craft that you can bet your butt that are available to replace it are through testing, and no one has a hint of what that was that flew over the pasture last night. It wasn’t an f-22. It wasn’t (yet) an f- anything. And yes, it was black.