So suppose we did learn how to live forever. That would mean everyone could do this and also every living being. So we would be living with coronavirus and other diseases for all time and going through repeated bouts of extreme discomfort (to put it mildly) with no exit strategy. The diseases we have are mostly other living organisms that are either symbiotic or parasitic with us. I wonder who would come up with the idea of somehow putting an end to this situation.