(Not passing judgement towards op.) Likely because many intelligent people are compensated more highly in the private sector.
We're constantly patting ourselves on the back for how intelligent we are. And yet we fail to address such systemic problems, which reduce our quality of life. This feels much more like stroking our own egos while letting ourselves off the hook, than an insightful analysis of the situation.
What that implies is that being especially smart isn't sufficient. If being smart was a powerful differentiator, then there would be an opportunity for smart people to enter politics. They would excel because they would have a competitive advantage over the less intelligent people who are currently in politics. They would have the smarts to avoid pitfalls, and profit from their powerful status and accomplishments.
But apparently they don't do this because every single person who is smart enough, has a better opportunity elsewhere. Every single one? I think the more likely reality, is this theory about insufficient compensation being the primary issue, is bunk.
We reward capitalism irrespective of how much (or little) benefit they provide to society at large.
All you're doing is dressing up selfishness as "intelligence", which is not the same thing.
Look at the net worth of someone like Dianne Feinstein (RIP) or Nancy Pelosi.