Ask this question often.
Several times a day, at least.
Endogeneity is a fancy term for confusing cause and effect. For not being clear about causation and correlation.
It's one reason why smart people make so many mistakes. We think A leads to B, so more A gets more B. While A and B may have been related in the past, though, it's not at all clear that improving A is going to do anything about B.
There is, for example, an extraordinarily high correlation between per capita cheese consumption and the risk of being strangled by your bedsheets while you sleep:
That doesn't mean that eating less cheese is going to help you not die in bed.