FOG...
The question is whether the things that Harriers/Gators have been used for will be done much better (or even as well) by a much bigger and more expensive machine that offers supersonic speed and stealth. In CAS, for instance, those qualities make as much sense as attaching a mowing deck to your Porsche 911 when you want to cut the grass.
When you do need those qualities, the CV will be present.