While funeral preparations for late Princess Diana were underway the call to end the representative monarchy in the UK got louder as it did before Queen Victoria and her German husband Prince Albert. The cost of a royal family, it's value to modern states amid Presidents is weight against the benefits to draw International attention to a country, giving stability and continuity to the people like no President could do.
History has seen many different forms of monarchies, some ruling in absolute fashion other accept the call of their people for an assembly to voice their mind or in modern times elected parliaments to make the royal head a mere symbolic figure of its country.
Unlike Presidents with or without political powers, the Royals give their people clarity and stability for longer adding a familiar face to processes that need a generation thinking spirit and the reassurance the much-needed change will come to pass thanks to the one leader's performance and personality. A King/Queen in the eyes of many is an emotional and spiritual attachment to a country better relating to the issue of representation of someone's country inside and cross borders.
Monarchies passing on their privileges from generation to generation inside the family have dominated the world and are mostly observed to date. This leaves room for royalists to be cheerful about the next better generation of Royals on any throne around the world while the one sitting on the same throne might not be seen by them of the same benefit.
I history in cases countries saw a royal more beneficial than a civil government by public voting or declaration by a limited group of people have seen their nations flourishing beyond expectations. King George I, founder of today's UK ruling house, the House of Windsor, was a Duke from Braunschweig-Lueneburg (Germany) before asked to rule over the British.
There is no government system to be called perfect but always the need for a nation constantly to consider all possibilities and implement in time the best solution of what can better the lives of the people on a certain given development level of society.