This is the phenomenon originally named "fake news" in the US during the 2016 elections. As in the comments that YouTube exposé you linked, despite what the evidence in the original investigations showed there were lots of accusations that this stuff was part of coordinated influence campaigns from outside countries. Threatened by this, Trump used the phrase against his criticism: labeling that the real fake news and any deeper discussion on it dropped from US politics.

The real issue is that these platforms have commoditized rumor in a way that gets around our cultural taboos about the practice.