This is a very foolish post. Most European democracies aren't much better than the United States and sometimes a by-product of it. A democracy like Germany is rather a product of its defeat, and France's democracy has been the root of all its problems ever since. They are no better than the US when it comes to money and votes, I'm sure. Both are built on political conceit.
>electorate has children
Not really. Sometimes the voting age limit allows children to vote. Other members of a society are not parents. They have their families, but not all families share the same status. A royal family is responsible to its sovereign office and normal families have other professions. A royal family resembles that right and honor between all families, but not all families are really meaningful. Ordinary people are ordinary people. The status of monarchs is their responsibility that they hold alone for the sake of their nations.
>So why believe that monarchies will tend to care more about the future
Because not everyone shares a common ancestral bond. The closest is race/ethnicity. The royal households have their history and ancestors to thank. If another family gains prestige and rises to the that status, they have become responsible for their history and their future. A royal household grooms the child for that profession like a professional father grooms his kid for his profession.
>the electorate has children as well as the monarch
The electorate also choose to have abortions from time to time. This would be controversial in a royal circle, I'm sure. They don't have the same responsibility of monarchs who have to provide an heir. They have that liberty.
>invest in education, protect the environment, and run budget surpluses
The EU doesn't have a healthy economic relationship, and these points are somewhat valid. However, they are no more powerful and before those European democracies existed there were already strong imperial powerhouses that innovated in education, industry, and science. Those European democracies are just a humiliation.
>America that doesn't care about these things
Thank goodness we have Merkel, Hollande, Macron, Theresa May, Tony Blair to save the day! More boring statesmen in their suits and ties. They get to take a nice rented out office and leave. Unlike monarchs are live for their nation and often share a history through their direct ancestors. Unlike monarchs who wear regalia and uniforms of service, emblems of their nations. Unlike monarchs who resemble their national character and have sovereignty, the character that consists with their very crowns and people. When people are sovereign, nobody really is. You get that clique of statesmen in boring ties and suits with tiny flag pins.
>the electorate
I don't think kindly of egalitarianism. It produces mediocrity.