AI is biased. It is biased towards the past. We feed data from the past into our statistical models and "AIs" and then present the results as though it's what will happen in the future. But the future will not be like the past, not exactly, and thus we have bias.

(As a philosophical question, why do we expect the future to be like the past? Well, because that is how things have worked in the past. And thus we arrive at a nice circular argument. :)