Give just one example of how any industry, absent any regulation, or left to its own,without any "watchdoggery" had conducted itself in a societally responsible manner.
I havent been able to think of one.
Humankind has a long LONG history of humans doing violence to humans for reasons considered noble, mandatory, respectable, and/or profitable. Some humans, not all, eventually evolved sufficiently to reason a better way of doing things and, via social contract, have agreed to limit their ability to do violence to others with impunity except within very narrow guidelines.
Our own Constitution is such a social contract.
I agree that you cannot trust all those involved in commerce and industry to do the 'right thing' without sufficient rules and regulations in place to prevent people from doing violence to each other and/or violating the Constitutional, civil, legal, unalienable rights of others with impunity.
I cannot believe there are none conducting business, especially those of certain religious faiths, who do not have a moral and ethical center that prompts them to do the right thing as much as is humanly possible. I have worked for such people. I have also worked for some who I think would have sacrificed their own grandmothers if they thought they could get away with it and make a profit.