A rangefinder can also do more than just range. If hunting on the ground in a "natural" ground blind, fumbling with binoculars to look at deer at moderate distances can be tough, with a nocked bow across your knees and while trying to keep movement at a minimum.
Think of a rangefinder as a good monocular. And since there are no good quality monoculars out there for hunting, a 4, 6 or 8x monocular in the way of a one handed rangefinder is a bonus.
If you don't care what kind of deer you shoot, then it really doesn't matter. But if you want to look at a browsing deer at 40-800 yards to determine if it's a button buck, if you planned on killing a female deer, or if you have some standard where you pass yearling bucks, the "monocular" aspect of the 4-6x rangefinder, while using only one hand, can come in handy.