Elections select the best manipulator, not the best leader or the smartest or most honest person. Elections are a manipulation contest, different candidates are trying to get the largest number of people to do their will, which is the opposite of the will of other candidates. This is a tug-of-war of belief manipulation.
The manipulator who wins will usually try to shift the rules in his favor so that in the next manipulation contest he will have an advantage. This is shifting the rules in his favor as an individual. If the best manipulators consistently get to power, they will shift the rules in their favor as a group, so the voting system will increasingly reward manipulation skills.
The best manipulators will obviously want the competition to be about manipulation skills, just like the strongest people will want it to be about strength and the fastest people about speed. Academics usually demand more intelligence in politics 🙂 This is not going to happen unless they gain power and change the rules to make the competition be about intelligence. To do that, they need to beat the best manipulators at their own game, which is unlikely.
People may think they have elected the best leader, but the manipulators will all want to make people think that they are the best leaders. So the belief that the best leader has been elected may be due to successful manipulation.
People cannot even define what it means to be the best leader, what qualities are sufficient. So the concept is mostly empty and ready to be filled with whatever meaning suits the manipulators.
In a dictatorship the competition will still be partly about good manipulation skills, but it will also be about ruthlessness, military and repression skills. The competition will be crueller and dirtier, it will generally not produce a better leader than the democratic manipulation competition. This is because one of the qualities of a good leader is usually compassion towards the ruled population, the desire to do good to them, while an assassination and imprisonment competition in an unfree country tends to weed out such tendencies.
Democracy is the worst form of government, except for everything else that has been tried. – Winston Churchill