Perhaps you have not experienced the thrill of unloading a pallet of concrete bags. It exists just between the range where it is too big a job for a couple bags in your car, but not big enough to get a truck.
Normal construction just isn't that straining to be wearing a exoskeleton.
Even extreamly heavy stuff like countertops, there's purpose built stuff to move these things the last 100 feet already.
In construction, if you know a heavy thing needs moved you procure the means to move it long before expecting someone to show up with a exoskeleton.
I'm not saying it's not cool. I just don't see a major efficiency gain. And, I don't see why anyone would want to rely on a exoskeleton to perform their daily job.