I don’t know why. I have small arms and fore arms and wrists. If I were to take another link off, the band would be too small, but as it is right now it has a bit of a slack. It never really obstruct hand movements, however since the dials knob is oriented toward my hand it sometimes dig in my hand but it’s not really an issue.
Ulnar stylus is the “bump”
I have thin arms/wrists and wear my watch close to my hand. Not a problem for me and can certainly see the face better when not covered with a long sleeved jersey in the cooler weather.