Are Duster rear bumper corner brackets important?

So I am in the process of replacing the rear bumper on my 1972 Duster and I am curious what is the consensus on the rear bumper corner brackets. Who is using them, who isn’t, are they even necessary? When I removed my rear bumper those corner brackets were in fact bolted to the bumper, but not to the car, so I am inclined to just omit them.