The Romans almost pulled it off, for a couple centuries at least. The emperor of Rome would name his adopted son as successor, but usually this “adoption” would take place well into adulthood of the adoptee, and usually after they had displayed their talent and abilities, i.e. like Mao “adopting” Deng or something.

And it only took one emperor to screw it up. Marcus Aurelius - of Gladiator fame and favorite of chud pfps everywhere - named his bio son Commodus as his heir. And kinda like how the movie shows, Commodus was pretty fucked up. From then on emperors often chose their bio kids as successors with the expected results.