Sorry, got a bit waffly...
In some cases it seems like cult behaviour. When someone is ill it is natural to question the treatment to make sure that the person you care about is getting what is best for them and understand why a certain treatment path is taken. There is so much misinformation about that it is quite easy to read something and then find multiple articles or sources to reinforce that belief and ignore factually correct opposite views. Rather than admit they were wrong they just keep on going with the lie.
There are almost certainly cases of voter fraud in the US. There probably has been at every election. However, never sufficient in number for people to believe that a conspiracy that an election was stolen. Getting people to believe and act on that theory and not believe the evidence showing their was no fraud is really scary.
Same happened here with Brexit. People have been told 'facts' and they believed them. We are now at the point where the lies are becoming apparent yet they now transfer the blame to the EU instead of the people who spread the racist crap and have enable the government to taser the country in the balls.
Mass protests against mask and lockdowns just seems so stupid. COVID deniers are in the same category as flat earthers and climate change deniers. They cherry pick the 'evidence' they want and ignore every thing else. There must be people who push this stuff for a reason. That could be political or financial or something else. Media doesn't help as they are there to make money and all to often go for the story rather than do actual journalism and find the background. Some media will try and stay on the fence and present both sides which is like me saying I am wonderfully slim and my wife disagreeing yet giving space for my argument that goes against all the evidence.
Edinburgh has cobbled streets. Once one becomes loose those around do too and quite quickly you do have a lot of bricks.
The solution? Taking down the misinformation would be a start. To often the likes of Twitter and Facebook allow stuff to spread before acting. The other is to find out who is wanting all this disruption and what is their aim.