Many countries went from being hereditary monarchies to one-party states ruled by a president-for-life (with or without ever having been democracies in anything but name). I wonder; what are modern dictators doing right that former absolute monarchs did not? I’ve thought about this and although I don’t have any firm answers, I have a few speculations:
First, classical monarchies based themselves on the feudal/aristocratic model where ownership of productive land was everything; consequently, as land became less important and industry more so they became increasingly estranged from the modern basis of wealth and power. Dictators today usually preside over corrupt bureaucracies which dole out contracts and business licenses to whoever pays the biggest bribes, of which El Presidente gets his cut or gains outright ownership of profitable enterprises. By this hypothesis, monarchies failed when they made the mistake of spurning the patronage of mere greasy mechanics and moneylenders.
Second, many dictators today are heads of parties that style themselves as revolutionary, and however decayed and corrupt still maintain the glow of the glorious uprising. A hereditary monarchy can hardly make the same claim.
Lastly, it’s difficult for power to be transmitted by heredity any more. Witness how successful dictator “Papa Doc” Duvalier of Haiti passed control to his son “Baby Doc”, who failed to retain it. In a classical monarchial system, if the heir to the throne is incompetent to keep power, there are any number of royal brothers, uncles and cousins who could seize power if a sufficent portion of the nobility backed them. Today a ruling elite would consist of whoever was smart and ruthless enough to gain and keep large amounts of wealth. Maybe some “old money” families to be sure, but also any number of self-made persons who’ve risen through the ranks, especially in the ruling party bureaucracy and it’s spoils system. Any of whom might feel that with cleverness, patience and a little luck they might be the king of the hill someday. In short, dictators might have chosen sucessors but almost never heirs.
The closest thing today to what I’m thinking of might be the house of Saud. And that’s a special case because Saudi Arabia’s wealth is almost completely dependent on a single extraction industry which is both lucrative and can be tightly controlled.
ETA: as a fictional example, there the Cross Time Engineer series by Leo Frankowski, whose protagonist Conrad Stargard introduces something like industrial feudalism to an alternate-past Poland and eventually becomes emperor of an alternate Polish Empire.