The only inherent advantage democracy has over monarchy is that it's less susceptible to political agitation. In this day and age political agitation has become a science, hence why democracies are so abundant while monarchies are few and relegated to retrograde areas or special cases. Monarchies in progressive countries were torn to bits for the fact that they were unable to contend with their up-in-coming political opponents.
One inherent disadvantage democracy comes with, however, is that it lacks long-term planning. The people who run democratic governments are only held responsible for things that happen during their terms, thus they tend to plan only for the short term often neglecting the long term.
