> efficiencies correlate with the quality and the quantity of infrastructure, not the ideological policies that dictate the ownership of the operators

I mostly agree. Infrastructure quality (including institutional quality) dominates. Ideology is usually cover for a lack of evidence.

But ownership modes do create different incentive structures. Full private ownership is famously terrible in natural monopolies. It’s a well-known market failure and folks who proselytize fully privatized utilities are stupid or venal. For many other things, however, private ownership works. A good example is package delivery. (Train operation is a weird case. The UK fumbled. Italy did not. On the other end of the spectrum, DB is a trash fire.)