Earlier quoted context omitted.
Related: Google is doing this. https://www.allsides.com/blog/audit-finds-evidence-googles-b...
Not that I fundamentally disagree with their results, but the study seems like it has significant bias itself. In what context is Fox News only slightly right-leaning? Anything critical of the current administration is not left-leaning either. In the past, most of these organizations have been critical of the Obama administration, but they weren't considered right-leaning then.
Politically, Fox does not stay put. To maximize market share, they always want to be just barely to the right of their main competition. Since that competition has gone quite a bit left in recent years, Fox has followed. By some measurements Fox is now even slightly to the left of the average American. Fox will immediately move back to the right if the competition moves right, because Fox can't risk crossing over.