And you know, I wouldn't be surprised if people hurling those accusations somehow believe that the lies and misinformation are one-sided and partisan. As if leftism has some sort of monopoly on Truth and Goodness bestowed from above.
It's really been sickening to see the media outlets just lay down thick trails of bullshit that is designed to distract us, to instill fear, uncertainty, and doubt, to make us hate one another, to keep us hanging on that channel or that subscription for the next tidbit. It's disgusting and manipulative, and the Right has absolutely no monopoly on those tactics.
Wikipedia is simply a microcosm of the prevailing zeitgeist, so they are as likely to cure systemic bias as a leopard can change its spots.
This thread is about media organizations, but I think useful context is that in non-polarized situations conservatives and liberals are similarly likely to spread political misinformation while in polarized situations conservatives are relatively more likely to spread political misinformation [1].