I've seen engineering use dynamite to, say, carve a road out of a rocky mountainside. But that's not
earthworks - that's roadworks
Dynamite is usually used to get something solid out of the way. Earthworks assumes you're working with "earth". Earthworks are created to capture
water and create a beneficial growing environment. Earthworks use a lighter, more creative and precise touch than one could get with dynamite.
I'm trying to envision a situation where dynamite would be useful and nothing is coming immediately to mind. Did you have a specific situation you were contemplating
Another drawback to dynamite is that it is usually controlled (understandably so) so I don't think it's a ready resource for most people, whereas hiring an earthmover is accessible in most places.