Only a two-weapon fighter or an archer ranger needs Dex. Or rather, needs to be built with Dex as a primary attribute. Nothing in the package gives you benefits based on it, and proficiency with medium armor means going with Dex above 14 is a waste (unless, again, you wish to be two-weapon fighter or an archer).
Any other kind of ranger, be it sword and shield, two-hander, polearm, whatever, can really just not focus on Dex, pump Str and Wis, and be fine (well, probably also pump Con too, if you're a frontliner)