This is why hereditary rule is so terrible. The Japanese have figured it out to some extent. It’s not unheard of for families without children or with incompetent children to “adopt” adults into the family to carry on the family business. Even that’s only slightly better though, meritocracy bc of capitalism and the nuclear family has probably done more to progress society than most people realize. Yes it’s not perfect, there’s nepotism, there’s greed, but we as humans haven’t figured out an alternative that’s been proven at scale yet.