Where I live if I want to travel north in the daytime I’ll use my compass, at night, the North Star. Not much of a problem starting out, but when I get near the top...a lot of miles in difference. Just a different topic on a public forum.
I like the topic...just surprised to see it. I had a little box compass years ago. Looked liked the same one that Einstein had.
Using a compass alone, for a hiker magnetic declination is not a factor. In the same way when using a map alone, is not a factor.
Once you start shooting compass bearings and then translating them to a map bearing, or the reverse, now you got a problem if declination is not compensated for. With say an 18 degree Easterly declination, the weary traveler might be off a mile from the intended point after traveling just a few miles.
Magnetic deviation from true north continues to be convenient for most people in the US despite a recent 30 years truly massive and very fast movement of the North Magnetic Pole from close to the north coast of Greenland near Canada all the way past the North Pole towards the Siberia coast.
From the US Eastern and Central Time Zones, that has little difference in deviation.
For far north Europe? Many degrees!