What do I base this on? Allotment of assets. What is the replacement for the A-10, which is 30+ years old? There is none. The F-35 is a replacement for the F-16, which does CAS, but is not optimized for it.
What new aircraft have been funded in the last 30 years? F-117, B-2, F-35, F-22, F-15E. The F-15E is certainly a F/A aircraft, but it is optimized for strike missions, not CAS in the FEBA.
Fighting a foe without defense's allows any aircraft that can carry a JDAM to perform CAS, but that all changes when the enemy shoots back. In such an environment UAVs are being looked at to take a bigger and bigger role. So where is the USAF’s priority? It appears to be in moving those assets to the Army.
That's why I question the Air Forces commitment to CAS.
The A-10 C is going to give them many times more capability. Read the June issue of AF magazine. It has a story on the A-10C and part of the title is something about "not going away." The "Charlie" is really something. It can carry smart weapons now.
You are assuming one needs to get up close and personal to provide CAS. That used to be true, but is not any longer. With modern targeting pods, it is possible to provide more accurate CAS from 30K than from 500 feet.