Given the type of people who complain about this sort of thing, do you really want to use words such as dominant.To play the devils advocate here,
we could word it as dominant and recessive genes not races/species.
Like those genes that exist in real world.
I.E.
lets say that Elves all get proficiency and expertise in Perception.
Humans get skill versatility in two skills.
Half elves then could get proficiency in perception(dominant gene) and one skill for skill versatility.
No expertise in Perception as that could be recessive gene and both parents must have it.