Why are most of the world’s monarchies in Eurasia?

Eurasia is considered the cradle of civilizations; the oldest states on the planet were founded here. In addition to northern Africa, evidence has not been found on one continent, but in the same ancient countries as on the territory of Eurasia. That is why, in the thinking of many, monarchical rule, even if it is only a conditional power (as in Britain), has a symbolic meaning. In addition, most of the other continents were colonized by the peoples of Eurasia, and the rule of the monarchs there was interrupted in the Middle and modern eras.