If Dragonborn gets Darkvision, then Githyanki should aswell ...
I mean, they have cat eyes after all ...
And from lore perspective they were breeded by Illithids as perfect slave race ... since illithids live in darkness, it makes no sense to keep their slaves blind ...
What they really need is a buff to their useless breath weapon.
I thought i hearwd somewhere that Dragonborn breath weapon get dmg boost in BG-3 ...
But maybe i heared wrong.

Instead of randomly buffing them, why don't we add the disadvantages that some other races have in DnD?
If you follow the rules, e.g. drow have disadvantage on all attack rolls when fighting in sunlight, gnomes have disadvantage when using big weapons like heavy crossbows, longbows, greatswords, pikes, ...
I like this one!