Before nav equipment was available to compute bearing and distance to the next waypoint formal (not by eye) navigation was done entirely on the chart. Track-lines were laid down, fixes were plotted, the course was adjusted accordingly.
If you switched charts and the was an error in the track-line and the fixes were no longer on the track-line the mate would just adjust the course and get back on track.
Once the GPS came along with screen and “highway” the mates began to follow that instead. No one told them to, they just did.
If the track line in the GPS and on the chart did not match, mates would follow the GPS and assume the paper track-line was wrong.
This can be seen when going GC, the fixes will match the track at the segment ends but arc away between segment ends (unless the 2/m used the steel globetrotter edge-wise). That is because the watch mate is following the GPS screen highway, not truly using the paper plot.
I recall being 2/m and if there was an difference between the paper track-line and the GPS the mate loved pointing it out. Before GPS they just followed the track on the paper and didn’t complain.
EDIT: change “waypoint” to “segment”