Race is clearly a social construct that doesn't really hold any explanatory power in modern societies. This should be obvious because there is no objective way to determine one's race.

The term has absolutely no clear use in any meaning; it barely makes sense in the most extreme of circumstances i.e. if you live in a predominantly "white" town and categorize everyone else as "black" or "asian". It doesn't make sense nor has any meaning for people who have received a basic education and understand science and history.

All categories are absiolutely not social constructs. If we categorize people by height or blood type then these are categories that can be objectively defined.

Whereas with race you have no clue which race you belong to, you cannot prove or determine what race I belong to. You don't even have a fixed list of races to chose form. Hence, social construct.