Physicists1 – usually old physicists – are famous for turning up in other fields and assuming that, because physics is hard and they – as physicists – are therefore smart, those other, lesser, fields must be simple and the people who work in them mere buffoons, labouring in the dark and unknowingly waiting to be enlightened by the great power of physics and the great intelligence of physicists.
This does not endear them to people who work in these other fields: partly because this kind of arrogance is not endearing, but mostly because they are wrong2. Of course many other fields are less mathematically demanding than physics. But that doesn't mean that they are simple problems merely waiting for physicists to solve them. For instance, joinery is unarguably less mathematically demanding than physics: does this mean that a physicist could simply turn up and somehow solve the problems joiners have spent hundreds of years solving? Have you ever watched a joiner at work? Because if you have you'll know how stupid an idea this is.
OK, you say, but that was a silly example, joinery is a mere craft skill and not comparable to physics3. So, OK, how about, say, climate science? A simple problem for any competent physicist to solve, surely? And some physicists really think that. And when they apply their physics toolbox to the problem ... they get the wrong answers. They get the wrong answers for at least two reasons: because their model is wrong, and because the real system is just really complicated and requires really complicated numerical models.
The Dunning-Kruger effect is a sort of inverse imposter syndrome, where the people who are least good in some area hugely overestimate their competence in that area. So, for instance, someone with a history degree (a perfectly respectable degree in a perfectly respectable subject requiring deep understanding, whatever idiot physicists may think), might become confused and think that, because they could do some simple-minded maths, they had self-taught themselves maths to postgraduate level and were, in fact, better than all but a tiny proportion of the people who had actually, you know, studied maths.
So what happens if you compose these things? What happens if a collection of people who are not even competent in some area but think they are far above average in it also think that their imagined competence entitles them to turn their hands to any other area where lesser mortals toil?
What happens? The answer is easy: simply look at Dominic Cummings and the entire UK government.