It doesn't exactly "burn the metal layer of the disc"; discs are made of several layers, and the coating on the layers is what's the problem here. Mass-produced cheap discs don't last long, at least not beyond a couple of years. See disc rot on wikipedia
I use external drives now; granted, they don't last that long either, but TB-sized drives are easier to manage rather than stacks of discs, and duplicating them is less tedious. Drives get larger and cheaper all the time, and I'm hopeful that more longer lasting storage will show up given the rate of advance in this field.