It's very simple: looks help, but they're not the common denominator.
A 5/10 guy with perfect game/personality/etc will almost always beat a 8/10 guy with no game/personality/etc.
However,
A 3/10 guy with perfect game/personality/etc will almost always lose a 10/10 guy with no game/personality/etc.
On the extreme ends, looks DO matter quite a lot, but for the bulk of the curve, the 4s, 5s, 6s, even 7s and 8s, game always is the common demoninator.
I'm often told by both men and women that I'm a pretty good looking guy, but despite this i've probably had more rejections, flakes, LMR, etc than the average looking guy has had to deal with, due to the way I've conducted myself around them.
When you're not on the extreme ends of the scale, looks only matter for with initial attraction, they won't do **** if your game is off or you are otherwise doing something wrong. It is true that a small minority women are superficial enough to sleep with a guy once or twice simply for being attractive, but that's about the only real benefit of good looks (unless you're a legit 10/10).
Getting a women attracted to you is easy, whether it be looks, game, status, wealth, etc, it's the maintaining of that attraction that requires real effort, and looks have almost nothing to do with that.