Compass nav is different depending on what you are doing.
For backpacking, the simpler, the better...just point me to mag north. The map does the rest. The only time declination matters (in my part of the world) is if you are traveling across featureless terrain...flat desert, dense forest, etc. Even then, most orienteering compasses have no markings or adjustments.
For flying, the compass needs to be compensated, and placarded for errors. Declination is figured "on the fly" since it changes as you travel, but is read off the sectional charts.
For sailing/open water nav, a compensated compass, but again, declination is accounted for on the charts. For sailing, the compass needs to read no matter the boats lean.
Map making, surveying, requires much more accuracy, levelness, declination, inclination, and good sighting. Pocket transits are works of art.
For diving, I like a baseplate compass board, with declination adjustment pre-set....it's like flying across featureless terrain, and becoming disoriented and lost is a real possibility.