I’m not sure that would make much difference. When you control the media companies (including social media), you control what people see and hear. When you control what people see and here, you control what they believe and how they act, to a large extent.
Which is not to say that it wouldn’t be an improvement, just that it wouldn’t solve that particular problem. At least not directly. Perhaps it would make it easier to implement systemic changes we’d need to truly address it.
Jeff Bezos didn’t buy the Washington Post out of a love for journalism, that’s for damned sure.