The logical conclusion of that is feudalism, and I think with more or less the same consequences. Basically:
• You'll get some good kings and some bad kings
• Some will be into exploration for wealth, prestige and to further an ideology
• Wealth and power will be passed down through families
• A person being a good king is probably a bad predictor of their great grandson being a good king
Democracy and a strong central government aren't an optimal solution to the distribution of power, but they do tend to average out systematic performance over time to produce less ups and downs. Technology and finance seem to be the largest pseudo-king making disciplines these days, but I'll leave musing over their relative distribution of good and bad kingliness as an exercise to the reader.