Because they were mostly sticking to just PHB.
Not really, for example they used Tashas floating attributes.
Yes really.
"Mostly" isn't "Entirely"
They "Mostly" were sticking to just PHB. Ergo, PHB version of Dragonborn.
So we are back at my original question why Larian used the basic Dragonborn instead of the updated ones.
Especially as the Tasha rules they did use are one of the reasons why dragonborn are underpowered, as previously they at least had a quite good ability score adjustment.
