As an odd speculation perhaps, but I can see (?) some factors making the Raptor obsolete if met by a force of an advanced nation.
1. Links. The modern fighters are all relying on links. Data needs to be fed to them if they cannot acquire the data by their own radar. Scramble issue. In a rough case, high alt nuke will toast...a lot of stuff. (computers)
2. Tracking by other sources than radar. Okay. The Raptor is about invisible to radar. But it does give some IR signal. And it is visible. And sound. And perhaps transmission. (radio, onboard radar, etc). Even tracking from top (Satellite looking at aircraft on-top, be it IR or visual). As soon as tracked...SAM's and such are fast on the road.
3. Daylight. Yes, it may be invisible to the human eye like a bullet, but not to modern equipment.
So, it is, in case spotted, a formidable adversary. The worst scenario is being locked into a close combat with multiple adversaries of similar equipment. Hence, threat 4:
4. Now, I ponder on RC fighters, which would be easier to build than Raptors, and may be in some years to come, a naughty surprize. And while many a supporter for the necessity of a manned fighter base their logics on the "must" of a ground link, - today, no fighter will do so much without one. (interception most important). Imagine the nightmare, - RC/AI light aircraft, interceptors/special air defence capable of more G's than any human, yet possibly powered by one, no life at stake (since the pilot is in his...bunker). Tracking could be done by the same equipment as a fighter, with further processing at the user's handle (which has no weight restrictions).
As a brighter side for the Raptor, it could have such...as an escort. Or decoy....
I got those ideas after watching a program on the History channel (I think) on future air combat. It almost looked like an F22 ad. Unforunately I cannot find it. It was like 90 minutes in 9 parts if I recall.