One of the main questions people ask about AI is about substitution: will come the time AI will undertake tasks humans do?
It's very important to understand the difference between applied and generalized AI.
Today and in the next 15-20 years we are talking about applied AI, means only special kind of tasks will be fulfilled by AI, but also when in maybe 20 years generalized AI will come (a machine will "think" like a human) there will be enough creative and "other" tasks for humans so that AI will not replace, but could extremely transform humanity for the better.
