Personally, I think a lot of theses posts asking for buffs to Dragonborn are asking for too much. Getting resistance to elemental damage is already a huge boon.

The argument that dragonborn should have the same abilities as dragons falls flat to me. These are attempts to make dragonborn overpowered relative to other races.

For humanoids, I think only Underdark races (drow, duergar, deep gnomes) should have dark vision. It really doesn’t make sense for surface dwellers to have dark vision unless they are also nocturnal and normally are only awake during the night.

I think a +1 bonus to AC or well scaled breath weapon are good options. However, I think it would be unbalanced to give them both abilities.