I've stated why I think constitutional change is necessary but I can see you're not convinced! Certainly either party could (and has) created advisory boards like the voice in the past. The trouble is that they've been dissolved in the past, and there's been no ATSIC like body since 2005. The third point in the constitutional change is important because parliament should have the power to change the voice. Say for instance it is found to only represent the 'inner city indigenous academia', then government may wish to change the advisory body to make it more representative of wider indigenous population. Another situation may be there's issues with corruption.