We are not the same and we are not all equal. This is just a fact of life present everywhere, not just races. Something being a social construct means nothing in terms of how real it is especially when we're talking people, to quote engels:
We regard the economic conditions as conditioning, in the last instance, historical development. But race is itself an economic factor. But there are two points here which must not be overlooked.
(a) The political, legal, philosophical, religious, literary, artistic, etc., development rest upon the economic. But they all react upon one another and upon the economic base. It is not the case that the economic situation is the cause, alone active, and everything else only a passive effect. Rather there is a reciprocal interaction with a fundamental economic necessity which in the last instance always asserts itself.
Race isn't just genetics but its intersection with civilization, class, and culture which is a product of shared economic conditions. Those are all social constructs as well, yet there's hardly been anything but clashes of civilizations, class struggle, and cultural war in the history of the 'one species'. The family is also a social construct, yet nonetheless fills a critical genetic role for modern society.
Some societies produce tribes and shamans, others produce nations and high churches. Some hunt in simple hierachies and never worry about winter, others have to defer gratification and have a complex society of classes because of agriculture and the social surplus it creates.