I think one of the critical changes in recent years is the rebuttal of factual events, as opposed to differing views on the interpretations of them.
For many years, political discourse was shaped around opinions on events - e.g. event A happens, someone think's it's a good thing, someone thinks it's bad. But that the event itself occurred wasn't (generally) called into question.
The dangerous element of the "fake news" narrative is that protagonists can now, point blank, deny that the event even happened. This is dangerous as it cannot be argued or persuaded against, it's literally "I'm right, you're wrong".
However for me, the real danger (exacerbated by Covid narrative in my opinion) is that this logic is being expanded to cover literally anything, things which were previously accepted as the child of science, logic and knowledge are now "up for grabs" so to speak.
Whilst I appreciate that progress must bring with it change and that mindsets change over time (thankfully in many cases!) I genuinely think the current narrative risks reversing much of the progress gained by societies over the last 100s of years. Scary times.