Non-Americans should not, and usually do not believe either. It's funny when Republicans/Democrats treat either as reputable.
They're politicking 101 made into 24/7 news media panic.
They're both charlatans and peddlers of lies and cheap tricks; they engage in propaganda and employ journalists who seem to believe that they're anything other than foot soldiers to stir up the masses against XYZ.
Everyone knows Fox News is trash, it's laughable when some continue to argue that CNN isn't.
Where XYZ can be anything, depending on which way the wind is blowing, sometimes it's each other, sometimes it's internal to the US, sometimes it's external
They're both plain ragebait. I wouldn't even take their world news seriously, mainly cause it's low quality. We have better options for mainstream news here, even though it's also under control.
I.e. US republicans most often won't believe CNN and US democrats most often won't believe Fox.
The point here is, there are plenty of topics on which CNN and Fox coverage is very very similar: off the top of my head events in Israel and Taiwan
And on those topics, plenty of people just "trust the consensus" (or what appears to be the consensus, in western media)
https://www.peoplesworld.org/article/out-of-bounds-how-media...