I drove many a mile on Michigan gravel roads. With a good hard-pack of snow, you could drive faster on them than the rural paved roads after a snow. For rural, low volume roads there's nothing wrong with a gravel road, but all the fuck-sticks that fled Detroit demanded paved roads "just like in the City". Fuck them, it's mostly rural farmland, and gravel roads are just fine.
The biggest problem with Michigan's roads are the number of freeze-thaw cycles they have every year. To the north, the ground stays frozen all winter, to the south, the ground doesn't freeze very often. In Michigan, you can have 2 or 3 freeze-thaw cycles in a week, which tears the ass out of an asphalt base, and causes heaving on concrete roads. U.S.23 (used to be all concrete) was horrible.....the slabs would be 3-4 inches different from slab-to-slab.
Not a damn thing wrong with a maintained gravel road......plus you get to get a new windshield or two every year!