What replaces it? Loitering missile drones + a big expansion of satellite imagery?
China has already developed what is effectively an ICBM designed to sink/punch through warships from above.
There is nothing stopping a satellite from maneuvering out of the way of an incoming missle, or for it deploying counter measures.
Satellites can be launched on arbitrarily large rocket boosters with an arbitrary number of in orbit assembly/refueling flights. Anti satellite missiles require that the missile can be deployed to a useful location that can’t be immediately disabled.
So in short your idea won't work in the real world.
It's a tremendous waste of money