Is it more advantageous to play a Dragonborn Paladin rather than a Human Paladin?
Each one has its strong points and weak points. I think the fact that humans are more versatile and more readily accepted around they would be the ideal choice for a paladin.
Dragon born paladins have some advantage in size and strength but one has to be careful with them as they can easily be a large instead of a medium creature this they are easier to hit and stand out more making them more of a target.
I would play either one with no qualms.
Dragonborn are made for paladins. The two stat increases they get as a race happen to be the two priority stats for paladins. I don't know of another race with stats tailor made for paladin like this. The dragon born are usually honorable so the paladin class once again is very fitting. Humans can make great paladins as well but they don't have all the advantages the dragon born have.
On paper because the Dragonborn, have a +2 strength, and +1 charisma, Paladin class would be optimum.
However, in the end it boils down to whatever the player feels is the most fun to play.
Even half Elf works well with the charisma bonus.