Why do we allow stupid people to vote, why are stupid people allowed to run our countries? Is democracy not broken?

Would it not make more sense for all governmental positions to be decided based upon a persons qualifications/intelligence/achievements in their field rather than an arbitrary popularity contest where the majority of the voters can barely understand the most basic political issues?

Can we not at least restrict people's right to vote based on intelligence?

I don't want my country's leaders to be decided by the pond scum of society.