I don’t know for sure, but I tend to think that the teaching of Land Navigation in the Army has suffered the same problems. Completing a full land nav course was quite an accomplishment back in the day. 10 or more klicks overland and hitting 10-20 points correctly was a feat that took skill, knowledge of topo maps, compass use, distance traveled, and some plain old luck.
GPS isn’t as critical as many here think. All modern jets and ships have inertial navigation systems with integrated GPS. The function of the GPS integration is to constantly update the inertial navigation system. Modern INS’s are very accurate even without the GPS updating, the ones on most fighters will only drift about .2 miles over a given hours flight time, ones on a ship like an aircraft carrier much less than that. Targeting systems are based off of the INS so if you lose GPS it’s really not going to do anything. GPS is also easily jammed so all military equipment is built with the knowledge that if a real war started with Russia or China you’re probably not going to have GPS available anyway. Inertial navigation systems have been around for a long time and don’t need external input like GPS, they work fine without it.