So you start a new character. You look into the starting passives - lets take the rogue as an example - and one of them gives you dodge rating.
Dodge is good right - you wont get hit! You put a few points, you venture bravely forth against a pack of mobs in which every single one hits you and you die. After you click the respawn button and review your chars cheet you realize that picking some dodge passives did absolutely nothing for your survivability, because dodge is balanced around a level 100 character which gets many bonuses for gear and skills and you need to have a dodge rating of hundreds to thousands…
The armor and dodge formulae really need to take into account your level or the area level you are in. Much like the game doesn’t expect you to be res capped on level one it should allow you to get a meaningful defensive layer out of your dodge and armor stats in the early game.
The graphs clearly show that area level play an important part in the calcs and that it requires very little investment for either to be good at low levels… (obviously Dodge is RNG vs armour but still).