Unregistered copyright has a lot of disadvantages -
1- Unregistered copyright holders are less likely to reproduce their original material.
2- In the case of unregistered copyright, proof of ownership of the original work becomes difficult.
3- Protection against copying or reproduction becomes difficult for unregistered copyright.
4- A lawsuit for violation cannot be filed unless your copyright is registered.
5- The owner of non-registered copyright cannot prevent anyone from infringing its rights unless they register their work.