What part of the PHB is telling us what racial traits are, are you thinking is my decision?
I didnt decide that those weren't racial traits. 5e did.
So to be clear:
Ability score increase: racial trait Immutable.
Age: racial trait. Immutable.
Alignment: racial trait. Immutable.
Size: racial trait. Immutable.
Speed: racial trait. Immutable.
Language: racial trait. Immutable.
Subrace: racial trait where applicable. Immutable.
Darkvision. Not a racial trait.
Fey ancestry. Not a racial trait.
Keen senses: not a racial trait.
Weapon proficiency. Not a racial trait.
Stonecunning. Not a racial trait.
Lucky. Not a racial trait.
Infernal legacy. Not a racial trait.
Breath weapon. Not a racial trait.
Gnome cunning. Not a racial trait.
So that means what exactly? What here is universal, what here can't be changed and what here can?