Anybody with a serious interest in protecting America's democratic institutions should pay heed to this article by a former Republican staffer who left his party in disgust. It paints a truly terrifying picture of where we are headed.
A government's perceived 'success' is the opinion of the governed. The form of government's 'success' is the opinion of the governed.
A monarch, Queen Elizabeth-I, did a damn good job of leading England; overseeing the defeat of the Spanish Armada, which allowed the British Empire to become a hyper-power through naval domination, along with her reign being a period of economic prosperity.
Another monarch, Napoleon I, nearly conquered all of Europe while at the same time having the popular support of most of the conquered. He created a revolutionary legal code that still exists today, albeit heavily modified, in France.
An Aristocrat, Otto Van Bismark, unified the German-states and established the first partially government-funded healthcare and retirement plans, successfully making Germany more appealing to the Germans than immigration to the Americas.
A Fascist, Adolf Hitler, allowed for rapid economic and military advancement of an unstable, debt-ridden Germany to super-power status in addition to creating a government that was extremely stable as long as the Fuhrer's underlings did not acquire too much power individually, which he was successful in preventing, something that is usually only attributed to Democracy. (and he was over-all a greater evil, but ignoring his racial ideology and racially motivated actions he was an excellent leader in most other fields until he started abusing amphetamines). He also nearly spread a banking system which cut out the private sector, saving citizens a lot of money and giving the nation far more control over it's currency.
A communist, Mao Zedong, succeeded in taking a China that was unmodern, war torn, and near-incompetent militarily and set it up to become a major industrial power with rapid economic success with a military capable of pushing back the UN+USA in the Korean War that later acquired nuclear weapons.
Would people under these nations choose democracy instead? Probably not. Those under Nazi Germany gladly rejected it (it was fairly obvious that the Reichstag was a rubber-stamp parliament). Tyranny often spawns from Democracies, with popular support of the people.
Furthermore, success could be interpreted as say, making the country more Religious could be seen as success if the people were Puritans.