Hereditary vs elective monarchy

I can see the logic behind an elective monarchy. Hereditary monarchy though seems like it far too dependent on a family line being filled with sane, moral people who have the countries best interest at heart. I’m not looking to argue and won’t be looking to change anyone’s mind. I just figured y’all could give me the best argument for why a monarchy should be hereditary. Any answer, even just an amateur opinion is appreciated! Thanks 🙏