A copy is just a copy, it can save you from being destroyed by some virus, but it does not allow for variations, manifestations of individuality.
Life perpetuates itself through diversity, and this includes the ability to sacrifice itself when necessary. Cells repeat the process of degeneration and regeneration until one day they die, obliterating an entire set of memory and information. Only genes remain. Why continually repeat this cycle? Simply to survive by avoiding the weaknesses of an unchanging system.