AI is biased because reality is biased.
ML gives you a picture of the world as it is - or rather the subset of the world in its training data, the selection and labeling of which also introduces bias.
All ML can ever do, therefore, is reproduce existing biases; it does this automatically and by default.
ML can never be made unbiased because you would have to account for every structural inequality specifically. At that point you might as well just have a person do it.