The US has not really done much privatization -- at least compared to the rest of the world (in part because a lot of those businesses were never nationalized in the first place in the US). I guess one example is Sallie Mae, and I don't have any knowledge as to whether Sallie Mae got better once it stopped being a GSE and became a private corporation.
There has been a lot more privatization effort in Europe, particularly with the national airlines. Here is a Cato Institute article on the pros and cons (and of course, because it is Cato, you can guess that it favors it for certain industries):
https://www.cato.org/policy-analysi...vatization-reform-lessons-abroad#introduction
That's an interesting analysis of Air Traffic Control -- citing Canada (hee hee) as the model for air traffic privatization. I'm not sure it really qualifies. It's a monopoly owned by a non-profit, with airlines and workers represented on the board. That sure seems like a public entity functionally, if not by law.
The article also conflates two forms of privatization, and two different rationales.
1. Get Congress out of the business of micromanaging railroads and airlines, because Congress uses those things as pork. I think this point is true and should be low-hanging fruit. Amtrak, for instance, is profitable on the Acela line. In my considerable but dated experience, the Acela line is a great service. But the rest of the Amtrak system is a disaster because it makes no sense. Who the fuck rides a train from LA to New Orleans? I once looked at the time required to get to Salt Lake City from Chicago by Amtrak. It was like 55 hours or something ridiculous (changing trains is required, as is going around mountains).
Now, if we could establish an independent agency to manage Amtrak . . . oh never mind.
2. Government is inefficient and the private sector is better. This is sometimes true. But as I mentioned elsewhere, there are some businesses where efficiency is less important than reliability. Red tape is usually a derisive term, and sometimes red tape is just a disaster on every metric -- but usually, I think, red tape increases costs and improves reliability of performance. Maybe you don't think that is a good tradeoff, but it should be within democratic control. If the service is privatized, we're subject to the private sector bean counters. What would stop a private ATC system from doing a ValuJet? From deciding that a 99.9% non-crash rate is good enough given the savings inherent in going to an all-AI system.
I think a great example of this is submarines. Well, submarines as presented in movies -- I don't know if they are real life, but what we see on the screen makes sense. In Hunt For Red October, the captain and political officer of the sub were both required to open the safe containing the orders. Inefficient? Yes. Wise? From the Soviets' perspective, yes. It discourages defection -- requiring the defector to commit murder to succeed. Or the repetition of orders. It took me a while to understand why, on submarines (and space ships like the Enterprise), the captain gives an order to a subordinate, who then turns to give the order to someone else. Why not just have the captain give the order directly? Because, I think, it reduces the possibility of error. Again, Hunt For Red October: if the captain gives an order to turn directly into a torpedo instead of away, it's probably a big mistake. The junior officer is in a position to ask, "is that what you really mean?" in a way that the guy turning the steering wheel isn't.
[I have no idea whether this is real life, but I think you can see the safety benefits play out in the constructed scenes -- which are plausible and probably grounded in
something.