Micrometers certainly make adjustments a breeze. You need .005" more? Just turn the dial the exact amount you need. Super handy for load development, or switching bullets.
With a regular die, you have to guess, adjust, guess again, adjust, oops to far, adjust, a liiiiitle more... etc. Every time you have to loosen the lock ring, turn the screw, tighten the lock ring. This is fine for a dedicated die for a dedicated load. Set it and forget it. Like for your bulk 9mm/223 load with the same bullet forever. Or your old 30-06 that you rarely shoot and only load 1 bullet anyways.