Why do people fall for unfounded conspiracy theories?

"Why do so many people believe Covid-19 conspiracy theories?" From that article:

belief in conspiracy theories is negatively associated with education and positively associated with religiosity. In a recent study on determinants of conspiracy beliefs relating to Covid-19, it was found that younger rather than older individuals, those with a lower level of education, … and less literate individuals were more likely to believe in conspiracy theory explanations. Those living in poverty are also more likely to believe conspiracy theories. The experience of social change and social conditions such as unemployment can also drive feelings of fear and insecurity, resulting in higher levels of belief in conspiracy theories.…

A belief in conspiracy theories is created by epistemic motives (the desire to understand our environment), existential motives (feeling safe and in control of our environment), and social motives (upholding a positive perception of ourselves and of our in-group). Conspiracy theories can provide apparently simple explanations for complex phenomena such as a pandemic or global warming.…

Making sense of our own individual role in a complex world is difficult for everyone. This may be even more the case if you feel marginalised, unappreciated or insignificant. A sense that you know what is 'really going on', that you are one of a few who truly sees things for what they are, and that you can ‘fight against the machine’ or simply share your insights with others, may help to restore a sense of significance, meaning, and value in your life. Linking up with others with the same insight can also be affirming and reinforcing. You may also feel the benefit of not becoming a hapless victim of the machinations of a powerful elite; standing your own ground, asserting your own worth, and being someone that attracts the (even sceptical) interest of others.…

That's consistent with this 2017 article on 2 studies:

more education was associated with less belief in conspiracy theories, and this seemed to be explained in part by more educated participants feeling more in control, having less belief in simple solutions, and having stronger analytical skills.