A puzzle for the OP, given that a Human's +1 to 6 abilities supposed to be equal to +1 to 2 abilities plus 1 skill proficiency plus 1 feat we can determine, that 1 skill proficiency might be equal to +1 to 1 ability and 1 feat is equal to +1 to 3 abilities (especially since many feats include +1 to 1 ability and +1 or more skill proficiencies). This equivalence makes a bit of sense as a basis for your point system, good so far?
The half-elf get +2 to 1 ability, +1 to 2 abilities, 2 skills proficiencies, darkvision, and other smaller benefits. So is this a balanced feat?
Vision of the Night: You gain 1 skill proficiency of your choice, +2 to 1 ability and darkvision.
That's obviously too much for a feat but somehow 1 skill, +2 to 1 ability and darkvision are equal to 4 +1 ability increases.
The point of this exercise is that D&D, esp 5e, is not built to be easily balanced with numbers. Even if you are leaving the races untouched, their lack of balance still informs the rest of the system in terms of what is a feat equivalent to.