None of us are equal in ability, but all of us are equally entitled to justice and certain basic rights.
When we talk about human equality, no one means to claim that all humans are equally smart, fast, strong, or anything of this sort. What we mean is that all humans equally deserve their rights to life, liberty and pursuing happiness.
Yet, when we talk about human supremacy over animals we pick intelligence and cognitive abilities to justify our treatment of animals. Why is it humans of differing intelligence are equal but animals can be abused and killed with complete disregard based on not being able to function on the same intellectual level as humans. No wonder we live in a world that is continually fighting racism, anti-semitism, and sexism. We tell children one message about how differences don't matter while role modeling the complete opposite. The belief in human supremacy is the virus infecting the hope of realizing a truly just world. Either we are all equal or our differences matter. We don't get to pick and choose when they matter in regards to the notion of equality.