This is EXACTLY the problem! Not just with you, but with a lot of people. When you refuse to trust the mainstream network, you are opening yourself up to being manipulated by fringe news sources- who are under no obligation to even report the actual truth, let alone report things fairly or accurately. Instead, you are led down rabbit holes of fringe theories, conspiracy mongering bullshit, and even led into believing outright falsehoods, long after they have been debunked. Let's be honest- non-mainstream news networks often have an even more blatant agenda than you could ever accuse the mainstream networks of having. Like, one of them, I forget which one, claimed to be the "Pro Trump News Network." How is that NOT propaganda; if it claimed to be the "Pro Jinping" or "Pro Biden" or "Pro Putin" network, would you still trust them to be fair and factual?
Mainstream news media has accredited journalists who are educated and well versed in the facts they deliver. They are required to check their facts for accuracy. Non-mainstream news sources are not accredited, often are not well educated, and are under no obligation to fact-check what they report- which gets people in trouble when they believe things reported by these "News" channels that are blatantly not true.
What people need to learn how to do is sort out fact from opinion. Stick to only the presentation of facts. CNN is good at this. As is NPR. However, both networks also have pieces that are clearly opinion pieces, and are labeled as such. If you don't want news with spin- AVOID opinion pieces and editorials- stick to pure reporting of facts. Fox news is also rife with opinion pieces, the only difference being, they often fail to acknoledge them as such, and present speculative opinions as "Fact." Non-mainstream news sources are far, far worse than Fox in this regard- hence you cannot trust them.
