Social media is full of all sides spreading misinformation, all sides arguing in bad faith, all sides jumping to conclusions etc. I will not attempt to argue that one side is better or worse in these regards, though, as a leftist, I naturally have my own beliefs on who is better and who is worse, but there’s a glut of these bad practices everywhere online so it would be hard to win the argument. I could list a litany of times the left have jumped to conclusions, or judged too quickly, or lacked nuance or…
This is an excellent question. I think Sartre's Antisemite and Jew gives a hint if you are talking about fascism. They don't care about truth. Social reality is a type of domination game. Being fair or honest isn't a path to any sort of benefit because they cannot feel satisfaction from achieving certain moral or epistemic goals of preventing harm or increasing understanding. They get satisfaction from something else. They're following different rules than the ones we follow, but they know the rules we are following and use them against us--e.g., claims if unfairness, etc. even though they don't believe in fairness.
The last two paragraphs mirror quite a few things I've read by reactionary intellectuals like John Michael Greer, Jordan Peterson, Rhyd Wildemuth, Paul Kingsnorth, Simon Sheridan, and others. Many of them speak of exactly such spiritual and moral truths, their primacy over material facts, and the supposed error liberals and leftists commit by putting such spiritual ideas in a subordinate role to materialism or ignoring them altogether. Thus many of them are deeply into Joseph Campbell, Carl Jung, Oswald Spengler, and similar mystics who offer emotional and mythical views of the world that to a certain temperament seem more real than physical reality.
EDIT: also consider the photoshop discussed in this article and the whole hysteria over "groomers", amd the broader history of painting leftists, Jews, and other Others as people who kill/fuck/eat children. I think to this sort of mentality, being led away from the reactionary's community by convincing arguments that said community is and does wrong, and being killed and drained of their adenochrome by the Jewish lizard people are spiritually the same thing. See also reactionary demonology.
I think that 3 is where the rubber meets the road. If one's left leaning one might obviously think of something as a joke whereas if you are coming from the other side one many not find it funny at all. A few recent examples might be Trump telling a slur to desantis or Ben Shapiro not caring about sexual satisfaction.
For the record I'm also left leaning by nature, so i fight my natural tendency a lot to try to see things impartially. I surely fail a lot.
Without a real assessment that's not based on one's own perception, it's hard to tell who fabricates the most. I could point to several leftist fabrications as well which could be used to refute the argument. But the main and most important point is that I think both extremes in the left and the right are becoming more fascist. And that's worrying. So while your article might be perception biased, the main question applies to both sides.