Kingdoms, at least as far as our knowledge goes, existed for several centuries ( that does not mean they were great but time tested).
Democracy is definitely better than them but it is hardly two centuries old.
Unless and until we try to find out what are the roles and responsibilities of democracy , whether all of them have been understood and addressed, if not , what minor modifications, improvements are needed further to enhance its value especially, in the context of fast paced changes in technological trends in the cyber world on the one hand and how to create awareness and educate the luddites struck in the cocoons of their presumed comfort zones and bring them around to adopt to emerging trends democracy cannot be sustained.
Democracy cannot afford to leave many missing the bus. This is where political strategies , administrative governance along with existing institutions be they religious, regional, academic , cultural etc all must be used or made to work to evolve syncretic systems to bridge the gaps and decrease the divisions.