If a satellite is in a very low orbit then any debris fall to earth quickly. Almost all cubesats have a orbital life of six to five years. So then it should be

If a satellite is in a very low orbit then any debris fall to earth quickly. Almost all cubesats have a orbital life of six to five years. So then it should be possible to shift the world's global satellite infrastructure to low orbits, even if the unlikely worst case would happen. You wouldn't have geosynchronous satellites anymore, but we could work around that. If every satellite we have put into space magically exploded, and the debris was magically moved to a high LEO altitude and evenly distributed to avoid any holes, then we could still launch through this orbit of death to higher altitudes with only a 1 in 1000 probability of impact. Much better odds than flying the Space Shuttle. Much worse odds than flying on an airline. That would still curtail civilization's expansion into space, though it wouldn't stop it.