For monarchy: It's stable, enduring, and is a natural form of government. People can relate to a family. Monarchies tend to be more peaceful than republics, and in peace and stability there is the ability for wealth to grow and accumulate.
Modern Monarchies generally don't have the political rubbish that an elected president provides because the head of state is stable and above the political process.
As a comment on the US electoral process, it obviously takes a great deal of time and lacks value for money and effort.