> Social scientists do need race-based concepts

Do they? There are places like France where the whole concept of race doesn't apply to humans. Race terminology is for things like dog breeds. Humans don't really have races in that sense.

This is exemplified by the fact that someone with a black and a white parents is said to be black, because of their skin color. Even if you are for example 1/8th black descent you are said to be of "race" black because of the resulting skin color. It doesn't make any sense as a scientific concept. Other countries have different classification, like South Africa.

We are one species with various ethnicities, usually mixed.

According to David Graeber, the concept of race conveniently appeared when would-be slavers in Europe were looking for justifications for enslaving Africans when the medieval Catholic church consistently held that slavery was wrong. The concept of race was helpful in arguing the position that while God's law applied to the peoples that the medieval church knew of, there might be human-seeming creatures to whom it doesn't.

The effects of race-justified practices were so far reaching that they can be said to shape our societies, just as decades after the abolition of Apartheid, most South Africans know exactly how they would have been classified. At this point, for social scientists to abandon race would mean we would live in a society with features that neo-fascists have ready explanations for and no systematic standard of evidence against which their claims could be exposed for the fantasies they really are. You need to have the concept of race before you can see why the reality does not support the claims of the racists.