I see more people "over-scoped" than under powered...99% of hunters could hunt their entire life with a 3-9x40 successfully. I am guilty of this from time to time which is probably why I have more than a couple higher power scopes occupying boxes now....hahaha. I'd spent my money on higher quality glass before larger glass (took me awhile to learn this myself). It's like the 1st time muscle car builder, he thinks a Holly 850 double pumper is what his 350 Chevy needs, regardless of everything else...LOL
My hunting 308's mostly wear 3-9x40 (older vari x iii's) except one that wears a 4-12x44.
Something else to consider is weight...nothing discourages me more from hunting with a couple of my rifles than the fact that they are heavy....nothing enjoyable about packing a 10 pound rifle...and those larger scopes are freeking heavy and add up quickly to overall weight.