What you're calling "left" is center-right in the rest of the developed world. None of those are left leaning. They are all pro-corporate, pro-capitalist, anti-worker "infinite growth forever" media. Some of the journalists who work for them are left, but the owners are largely conservative and force them to cover Democratic scandals just as much as Republican ones, while Fox News and other conservative media outlets just outright ignore Republican scandals entirely.

If mainstream media in America was left, Bernie would have just finished up his second term.