I wasn't really bringing social construct into it because I don't think it is greatly relevant. Race isn't entirely a social construct, it's more akin to sex. You are born with the genetics of your heritage much like you are born with the genetics of your sex and neither changes just because you have a surgery. Perhaps heritage would be better to use than race. North African descent, Japanese descent, Scandinavian descent, Samoan descent, the heritage of each of these would impact your genetic makeup and things like healthcare much like sex impacts the type of care you may need.

There is plenty more nuance to this but that's my general opinion on why they differ.