Take dunning-kruger for example. Yes, it was not shown that people of low ability rank themselves higher than those of high ability. But it was shown that people of low ability rank themselves higher than they should, and that makes dunning-kruger’s popsci version right enough in many circumstances where it is used to make a point.
Or take the findings on happiness. Yes, money can make you happier, contrary to prevailing opinion. But other factors affect happiness as well if not more, so if you have to choose between money and other things, often times the other things will make you happier. Again, the popsci version of “money doesn’t make you happy” is right enough to be useful.
Same thing with climate change skepticism. When you first start digging into the better skeptic arguments they seem to be onto something, but as you dig down into the details and peel back the layers of the onion, the popsci consensus view of climate change turns out to be right enough to be useful.
I’ve come to the conclusion that these false trueisms hang around because they are “good enough”. It turns out the turns outs are much less insightful than they seem.