A solution would be, even with these massive hitboxes, that melee have more damage swing. Between +5% over a ranged, and -5% over a ranged, based on how competent the melee player is at doing melee-specific things like, idk, positionals? So if you just stood on the boss's arse as a melee, you'd do the same damage as a same-skilled, same-geared ranged. If you do the positional dance, you eke out a little extra damage from your class. Except SE is deathly allergic to things that give players a way to express skill like positionals, hence they keep adding more ways to avoid having to deal with them, up to and including having bosses that just don't have any at all