What does assigning a value to a google analytics goal enable?

GA values are your own value of what a goal is worth, its a little like saying a score for something - its perhaps worth doing if you've maybe 5 contact forms and some are worth more as conversion points or leads than others - eg they are further into your funnel and user intent than others. so you can give them a higher value. You can thne understand month to month how your funnels are working.