And upgraded F15's and F16's are more than capable of doing that within our own territory.
No, they’re not. There is no way to add stealth to their airframes and engines, and if you look at the list you’ll note that a lot of the F-16 kills have been via IR missiles. Bolting a new radar on and adding new weapons carriage capability is just like converting merchant ships to be carriers - it never really works out.
Also, two F-15’s have been lost to ground fire in US service.