In my opinion more would get done faster with less of a long period system. It would make it simpler to do things and have foreign relations and all. It would also bring easier and straightforward resolutions to conflicts and problems because it would be the kings say and that's it.
It didn't work. And the reason it didn't work is because nobility is an inherently oppressive concept — the idea that you can be born higher than someone is an insult to the idea of universal human rights. The oppressed ‘low-borns’ would eventually rise up against their kings again and overthrow them and install democracies.
It's been tried throughout history and it's failed for numerous reasons. Not only do the people of the country have almost no say in who leads them, but the succession is based on blood lines, which is completely idiotic in this day and age. Why would anyone want to live in a country ruled by possibly incompetent leaders chosen by mere accident of being born to a bunch of lucky people?