Humans needs, wants, and desires can't be "completed". AI robots might be able to meet a set of our current needs but we, as human beings seeking more pleasure, will expect more once they are met and a new set of needs, wants, and desires will open up. Humans will have a purpose - something to strive for, even if the AI robots are really productive. Few people live with a purpose today not because of technological progress but because they made the hard decision to live by their own values. To live according to one's own values is what makes life purposeful but most lack the cojones and the mind to do so. Purposeful humans will always exist, regardless of technological innovations, as long as the choice to act rationally and courageously is made.