The technique is still valuable. I.E. If you frequent an area plagued
by occasional fog, RDF observations recorded during periods of good
visibility would be useable when conditions were bad, even if GPS and
actual charts disagree. This presupposes that you can survive the trip
on a good day using traditional methods.

Preserving options is a viable method. Relying on a single method that
can not be absolutely guaranteed in a case of dead batteries or gps
instrument is an invitation the fates will not ignore indefinitely.

Terry K