Unless a Royal Commission is likely to produce useful outcomes, there is no point. What benefit could a Royal Commission into the NBN deliver, except perhaps some heads on platters? Even that seems highly unlikely to me - those who benefited from the downgrading of the NBN are not silly enough to sully their hands directly.
As for a Royal Commission into Privatisation, that makes a lot more sense. It should be asked to look at the long term costs and (cough) benefits of the sale or outsourcing of public goods and services, as well as how these decisions have been made and whether taxpayers have received value for money. It might also consider the operations of the ‘Productivity’ Commission, and tying of Commonwealth payments to state/territory asset divestments.
Maybe a Royal Commission into Smaller Government could also be formed, looking again at long term costs and (cough) benefits to the taxpayer. A Royal Commission into the Regionalisation of the Commonwealth Government, looking in particular to the move of the APVMA into its minister’s electorate?
The current government was keen to institute inquiries into behaviour of unions on construction sites, but ignored the behaviour of builders and approvers - that’s worth looking into.
The real question with all of these potential royal commissions is whether any government has the will to dig into the sins of the past - which include their own.