The error message indicates that the CSM user's TSO userID does not have the authority to perform the setuid function.
During a product installation if a USS directory needs to be created it will switch to between the CSM userid to create the USS directory and the user that is running the installation task. It is the CSM userid that requires UID(0) superuser access. The only alternative to that is you can configure CA CSM not to use UID(0) when running. This is documented in the Set Up CA CSM User ID Without UID(0)
Set Up CA CSM User ID Without UID(0)