Low power allows you to pick up your target faster. Better for close range. Also allows you to shoot with both eyes open. Faster target acquisition. Red dot type "scopes" are great if you don't need magnification.
I used to think scopes were overrated, but then my brother in law and I got into a group of mulies as the light was failing -- he had a scope on his rifle and I didn't. He got his deer, but I couldn't see the front blade reliably enough to take the shot. I've been a scope hunter ever since.
Of course, after a few years of that mentality I hunted whitetails in the woods of Alabama. My son and I jumped three whitetail that exploded out of the brush to our right and bounded off to our left just a few yards away. I snapped my rifle up, but all I saw was tree branches.
There's no solution that works every time. Sometimes you need both.
As a Taxidermist I look at hundreds of Whitetail Bucks every year. I know that I have seen many different ways people judge the size of racks on live deer. I think for the most part they all are pretty close. I'm going to give you some measurements that I have noticed being right on in just about every deer. We have used it in the last couple years and have only been off by about 5-6 inches. We do study the deer while bowhunting so we get a little more time to look at them....