Democracy is a failure, Benito "Il Duce" Mussolini once crowed, while boasting that he finally got the trains in his native Italy to move on time.
Democracy is the worst system of government, except for all the others, British Prime Minister Winston Churchill wryly opined.
True, in terms of promoting efficiency, no system of government could be worse than participatory democracy. All that debating back and forth among different parties seeking to advance their own agendas at the expense of the state and the people--how tedious and wearisome. Yet consider the alternatives: one-man rules inevitably leads to rule for one man, the ruler himself. From Kingdoms to dictatorships, men are incapable of restraining themselves to rule in the best interests of those whom they claim to serve.
As for rule by an elite or a select group, history has recorded more of the same, just on a more widespread field, in which the few rule on behalf of the few, dispensing with the needs of the many.
Giving the many a hand in leadership is a tricky affair at best. Even during the Golden Age of Athens, only free men were allowed to vote, the same political class which put the free-thinking Socrates to death. Not the greatest assurance for direct democracy.
The Framers of the US Constitution understood that rule over as wide a nation as the United States would render impossible direct democracy, certainly of the kind practiced in Ancient Athens. Therefore, a staggered Republic representing popular, statewide, and elite interests was designed, with checks and balances to ensure that no one branch of government, and no one class of society, gained full power at the expense of the others.
What was the result, this Federal framework for Government? A system that was essential and functionally dysfunctional. Members of Congress would be forced to negotiate at length with their counterparts in two different houses, then seek the approval of the chief executive, who could veto the law if needed. Accepting that men are not angels, as Madison famously remarked in Federalist #10, the US Constitution channels man's selfish ambition against itself and promotes outcomes the least detrimental to the federal government, the states, and the people.
A genius design, the United States Congress, Presidency, and Judiciary compete with each other for mastery, thus taming one and another and functioning de minimus in the best interests of those they govern.