Privatization works on many things

It works at turning private profit for private, sociopathic investors, almost never at improving or even maintaining a formerly government run service.

And the governmental service almost always goes to shit because it was defunded to cut wealthy investor's taxes at their demand, leading to cries for privatization by the same wealthy investors when it goes to shit as a result.

Effective grift if you have the lobbyists, the bully pulpit, and no conscience or humanity.

Market capitalism belongs in optional products/services, like fidget spinners and massages. It doesn't belong in prisons, healthcare, utilities, roads, etc, because private industry is all about getting maximum return they can get away with at the product/services expense, and finding new ways of giving even less while pocketing more, even if that means buying courts and politicians with that profit to make it legal.

Despite what they say about themselves, market capitalists have antisocial motivations in practice. They're want to own everything, purely out of ego and greed, and it will never be enough.