Question About NDEs

First, I would like to make clear: I find NDEs absolutely fascinating, but I have a hard time wrapping my head around the fact that people are actually dead when they have them. For example, why might NDEs be so rare if they are actually an accurate description of the afterlife? Why do some people who go through cardiac arrest have no NDEs at all?
I'm not so sure NDEs are all that rare. But I do agree that not everyone undergoing a cardiac arrest reports having had an NDE. That could be due to loss of memory, as you suggest, but one point is that anyone having had a cardiac arrest and lived to report on it has - well, lived to report on it. Maybe only some of them got far enough into the process of death that they experienced an NDE?