So we already in the wunderwaffe phase ?
https://en.wikipedia.org/wiki/Focke-Wulf_Triebfl%C3%BCgel
This concept has brainfarted it's way into the ether regularly over the years: VTOL from muddy field! Pop up point defense! Exotic untried tech.
Leaving aside we already have trailer mounted missile launchers that do much of this mission, and that motorways as austere runways have been part of Swedish aviation doctrine for decades, it conveniently forgets that there's a lot more to flying military planes than the flying. Delete the runway by all means, but you still need to fuel it, arm it, store it, repair it, move it about. The personnel, equipment and logistics for all that still requires a sizeable and bombable ground footprint. Temporary dispersal to muddy fields would be possible in extremis but logic and efficiency dictate that you're gonna want to concentrate resources in peacetime, so you've still got a largish airbase with crew quarters, hangers, maintenance shops, fuel and weapon storage etc, everything but the runway.
Want to cut that ? Integrate the fuel and armament in the package and make it single use ... and you've got a missile again.