Any company that is so important that its collapse would cause extreme harm to society, it shouldn't be privately operated. It also shouldn't be a for-profit organization since other things obviously must take priority over profit.
It also shouldn't be government owned, or it will end up being filled with political appointees, run down, and then shut down out of spite and partisanship. Or privatised for a song to a donor. The correct thing to do with the Standard Oils of the world is to break them up into small pieces and allow competiton and prevent collusion. Private or public, for-profit or NFP, monopolies cannot be trusted.