at 100 meters away, his arrow will take 1 sec to get there, tanks can drink a cup of coffee while taking two steps on the side, and will miss.
you can’t compare that potential Damage to actual damage. Mccree getting a dmg reduction at range was because his bullets are hit-scan you can’t dodge if his mouse is over your head, hanzo’s projectile is not, so if you notice a hanzo firing at you at 100 m away, you have time and can dodge it.