Reincarnation is in my opinion an overly simplified concept, designed to be easily understood and accepted by the general population. But the theory of reincarnation falls down sharply when closely examined. That is, if you understand how standard linear time sense behaves in higher dimensional levels, i.e., time sense fluctuates.
As far as it goes, the theory of reincarnation is clear enough to explain some very complex esoteric matters in a simple way; without giving people headaches whenever they think about it. It also allows for the illusion of the continuation of present consciousness, unchanged and progressive, with only an occasional memory loss to mar its course; marking the division between each Re--Incarnation. This makes it easy for people to accept the bones of the incarnation process.
It gives them the benefit of a rational afterlife belief-system containing the simplified essence of the whole truth. This allows a measure of independence and security, and a reassurance of the continuance of self, i.e., life after death and reincarnation is a kind of immortality theory that people can easily accept.