Can you think of reasons why more complex organisms cannot give rise to new individuals through regeneration?

(N/A) Simple organisms such as $Hydra$ and $Planaria$ are capable of producing new individuals through the process of regeneration.
The process of regeneration involves the formation of new organisms from their body parts.
Simple organisms can utilize this method of reproduction because their entire body is made of similar kinds of cells,where any part of their body can be formed by growth and development.
However,complex organisms have an organ-system level of organization.
All the organ systems of their body work together as an interconnected unit.
While they can regenerate specific lost body parts such as skin,muscles,or blood,they cannot give rise to new individuals through regeneration because their specialized cells are not capable of forming an entire organism from a fragment.