Well,a number of places did do it,like the HRE for example.Frederick II of HRE did not succeed his father to the throne directly--he succeeded his uncle even though he was already elected King of the Romans when his father died.but Otto Von Bismarck preferred a weak monarch and political crisis because it strengthened his control on the contry. Changing the constitution to allow Prince Henry the throne is a bad precedent to set.
no monarchy has avoided the eldest son of a king over the king's brother.
But I agree,after the early-modern period where states are more or less quite stable,people simply don't pass the throne over someone higher up in the succession order.