What you probably saw in days of yore were jets transitting to and from the Wash air weapons ranges. Since we don't practice many low level weapons delivery profiles any more there is less requirement for low level transits.
There is also one less Wash weapons range now and Coltishall used to provide a fair amount of trade.
Rest assured the Air Forces of all hues are still able to bomb and strafe the bad guys as accurately as ever (more accurately in many regards). You just won't see them as easily.
BV