If you want to prove it to yourself, as an exercise, take a good character (let's say dwarf or storm axe or mace) and an equivalent evil character (duergar or fire axe or mace). Build an ideal set of gear for each, but to control for the great unique or unique-ish items both sides have, don't use anything that there aren't at least, say, three of.

(Warrior's easy; if you get into mage gear, it gets a lot worse for good. If you dip into uniqueish mage gear, it's downright ugly. Add in Hell and it's like not even playing the same game.)