I am not sure about PC but this thread is kept ticking over by you and me
There is confusion between what the constitution is and what statutory law is. The Australian constitution, like the Magna Carta, is a hodgepodge of wishful thinking, intentions, useful measures and explicit instructions. I think that in my lifetime every government has violated the constitution by not holding a sheep census (it must have been an important topic in the 1890s).
The intentions are that the High Court of Australia is the foremost court in the Commonwealth and all other courts are subservient. You will note that the constitution does not mention how many levels of courts there should be, how they will operate, what matters come before those court (one exception and I will get to that), how many people will work there, why those courts are needed, where those courts will sit, etc. This is why when I was in my teens there was no Federal Magistrate but Howard created by, statutory law, the Federal Magistrate. The exception to the preceding is that the constitution explicitly creates a court for resolving industrial disputes and AFAIK is the only constitution in the world that does that. So for me creating a Voice to parliament and the executive is no different to the many intentions already in the constitution.
So why have intentions rather than explicit diktats? Well it enables the governments to create and modify via statutory law the organisations to fit the problems of the day. So the diktat to hold a sheep census is no longer valid but that will require a referendum. A better wording would have been for the government of the day to ensure that agricultural businesses have sufficient information to enable the sustainability of the industry - which is what happens in practice. BTW the constitution does not mention ministries other than the Chancellor of the Exchequer (popularly known as Treasurer) and a Minister of War (more commonly known as the defence minister. It does not mention the PM or any other ministry, in fact it barely mentions how the government ought to be organised.
You mention that there are already organisations that have a similar role. There is one major difference back in the day there was ATSIC which was in effect a parliament of sorts with no powers. And they were noisy. Hence one of the first thing that Howard did was to abolish it. You will have noticed that Senator Price at the beginning of the No campaign said that it was corrupt but when she was told that if she repeated that again she would be sued for defamation as no corruption charges were ever laid and none were found she never repeated it again. So under Abbot as minister for Aboriginal Affairs (and women) the indices stagnated - lots of TV noise no action. So how would a Voice be different? By being constitutionally mandated it could not be abolished and a parallel to that is the industrial courts (Fairwork Australia) for which there was a big push to eliminate it in the 90s (IPA headed that monster) but as it is constitutionally mandated it would need a referendum hence the IPA gave up and instead pushed for it to be stacked with Trumpists.
So how would a Voice impact me? Let's take the recent case when the government lifted the alcohol ban in Alice Springs. The locals were saying not to do it unless there were some other measures in place, the NT government was saying that in principle it was a racist piece of Federal legislation, the Morrison government agreed and then it all went to shit. So here I am in Melbourne thinking that the NT Minister is a tosser and that she had not put in place an alternative but more importantly how come no one in the Senate queried it? So what that tells me is that the Victorian senators are useless dills.
There is another aspect to the voice which goes beyond the First Nations people. Until recently I had to travel for work and I went to disadvantaged areas of South Australia where I met professionals who were embarrassed by where they grew up. I saw kids with little prospects and the social problems associated with those areas. And none of them were First Nations. My take is that what ever programs that are effective will be expanded to assist these kids.
As far as citizens having a voice through their elected parliament? As the 2010 state election was approaching the Coalition had a much tougher gambling policy. James Packer called Ted Baillieu, the leader of the opposition, spoke with him for 15 minutes and the policy was shredded. 20 years later we found that Crown was breaking the law and that Packer was not a fit and proper person to hold the gambling license. Gina Reinhart gives Barnaby Joyce a $50k cheque for being a good bloke but to whom? Do you have that kind of Voice?
So I am voting yes to the voice because the intention is that constitutionally the governments cannot abolish it. I would prefer that the Voice be to parliament so that the government of the day cannot hide it and I can judge them on their performance because I will have access to the thinking of the locals and see effectiveness of the policies.