If people are seeing relapses, then vaccines are far superior to natural immunity. Right. That's an advantage. The spike protein is the one part that the virus CANNOT change without becoming less infectious. So natural immunity might render you immune to an epitope of the virus that is inconsequential. A simple mutation can change that epitope, and the virus will be just as infectious - and you will have no immunity. Spike-targeted vaccine immunity cannot be defeated unless the virus changes the spike protein - and at that point it will be less infectious.