I get news from all of the providers you listed, but they don’t produce the content. The actual content is from the big media companies like CNBC, CNN, Fox News, WSJ, and NY Times.
These online media are content aggregators. They help socialize and propagate narratives, but they don’t produce narratives. They certainly amplify the echo chamber effect.
> big media companies like CNBC, CNN, Fox News, WSJ, and NY Times
Of those, the six companies mentioned by the grandparent (Comcast, Disney, AT&T, Sony, Fox, Paramount) only own CNBC and Fox. CNN is owned by Warner Bros, WSJ is owned by News Corp (of course, the link to Fox through Murdoch is relevant), and NYT is its own company.
These online media are content aggregators. They help socialize and propagate narratives, but they don’t produce narratives. They certainly amplify the echo chamber effect.