I have never been in the RAF (tried to join in 1973 but they were convinced I was KGB
) but I would guess that modern pilots don't navigate the way people used to, especially compared with the RAF as it was many years ago.
From what I hear and read, RAF missions were characterised by chronically tight fuel margins. If you fly a jet which has 1-2hrs of fuel, and you are navigating visually by dead reckoning, and you are supposed to do this in real weather, then you need a very robust system, comprising of highly selective recruitment, excellent pilot training, and strictly operated procedures. You also need the D&D 121.50 system which modern GA doesn't need.
GA is very different. Pilot training is very basic. Most "spamcan" missions are characterised by a poor knowledge of how much fuel is in the tanks at any point in the flight; this is dealt with by being very conservative on range and thus wasting much of the plane's capability. And there is a small % of GA which has accurate fuel metering, linked to the GPS flight plan, and they don't need these methods to plan diversions.