Just for the most ready to hand example for me, PG&E in SF vs public electricity utilities on the peninsula - the privatized electricity costs twice as much per kWh - and of course it does because the PG&E CEO needs to make $17M from somewhere, the share price needs to go up etc. the rich need to skim from the top, that makes the cost higher.
If you have an essential industry the cynical play is to privatize to save cost, then do a bad job and then effectively make your losses public through bail-outs while still making profit.