Don't the LEO objects have a natural loss rate (I.E., so many objects will soon be vaporized as they fall back into the atmosphere)? Those objects are designed

Don't the LEO objects have a natural loss rate (I.E., so many objects will soon be vaporized as they fall back into the atmosphere)? Those objects are designed to have a shorter lifespan (typically, ignoring the ISS). As for the GEO objects, given their fixed station over earth, I imagine there is less path-crossing, which would reduce the probability of an impact. Assuming the LEO objects are a major danger to something critical like the ISS, what would be the added cost of shielding? How much impact should the material be able to absorb, and what would that weigh? As for the economics of satellites, shielding seems like the next-best option to expensive tracking and safe decommissioning of all objects, provided the shielding material isn't too heavy as to be cost-prohibitive.