Sure, but who is going to have a fair look? Someone who is employed by the company or someone who is independent?

VW faked their emissions - EPA uncovered it. Google is harming people with bad AI models - Google is uncovering it?

This works if the company is actually interested in finding the mistakes (i.e. MS finding security bugs in Windows), but not if the findings threaten your business.

MS has an interest in fixing security bugs, because it makes their product better.

No big corp has an interest in fixing their ethics, it's usually bad for their profit margins.

Actually it wasn't even the EPA that uncovered it. It was academia. Corporations and governments just don't have the curiosity built in to their culture that academia does.