Well, the brits eventually decided against it after a thorough investigation found it to be a waste of money - "a January 2018 report by the National Audit Office found that the UK had incurred many billions of pounds in extra costs for no clear benefit through PFIs". https://en.wikipedia.org/wiki/Private_finance_initiative#End...
Another antifeature is the lack of transparency. The costs and operations of the private company aren't public, which means the public doesn't know if the quality problems are due to skimping on costs or mismanagement etc and don't get the feedback necessary for decisionmaking for subsequent contracts.
Regarding your airline analogy: my criticism wasn't about the private sector, my criticism was about copying it (poorly) in the public sector. There's things to criticise in the private sector side accounting incentives as well but it's a different kettle of fish.
Britain is also uniquely bad at government contracting. As we can see in detailed studies about cost of transport engineering.
As with everything things can be done well and can be done badly. And it really depends on this exact situation and the exact contract.
And both well done likely not that different in cost and other factors need to be included.
In terms of transparency having an isolated outside of government structure, you can potentially be more transparent as you can get detailed contracts down to item levels and have all those things be public. This is done in other nations when it comes to transport projects. But it of course depends on the government writing the contract to demand the level of transparency.
Another antifeature is the lack of transparency. The costs and operations of the private company aren't public, which means the public doesn't know if the quality problems are due to skimping on costs or mismanagement etc and don't get the feedback necessary for decisionmaking for subsequent contracts.
Regarding your airline analogy: my criticism wasn't about the private sector, my criticism was about copying it (poorly) in the public sector. There's things to criticise in the private sector side accounting incentives as well but it's a different kettle of fish.