I suspect there's a reasonable argument to be made that under certain circumstances, democracy is a substantial barrier to optimization of governance. Between Soviet/CCP long-term planning capacity and the fascists' making the trains run on time, industrial totalitarianism has a track record of getting the job done.
That said, all that job-doing is at the mortal expense of anyone who disagrees, stands in the way, or can be scapegoated for standing in the way. Also, woe be upon you if your leadership selection process picks a dud (compare the damage an incompetent megalomaniac leader in a limited democratic system can do to the same result in an absolutist dictatorship).
Singapore is a democracy, claiming otherwise is just an idiotic insult.
You see the pattern of the same group holding power for a very long time in some countries, in particular in times of high growth (rather than oscillating between blocks like the US).
For example LDP in Japan or the socialdemocrats in Sweden.
It really doesn't mean that they are not democratic.
That said, all that job-doing is at the mortal expense of anyone who disagrees, stands in the way, or can be scapegoated for standing in the way. Also, woe be upon you if your leadership selection process picks a dud (compare the damage an incompetent megalomaniac leader in a limited democratic system can do to the same result in an absolutist dictatorship).