I clicked on the health tag and found this post. ;) AI is also one of my interests. Anyway, I think this is going to happen much sooner than we think.

AI has just surpassed humans in several fields this year that many people didn't think was possible (image recognition, speech recognition, diabetic neuropathy diagnosis). By 2020, there will be a lot more such fields where it would make a lot more economic and social sense to replace humans with AI.
For example, would you be willing to accept a 95% discount on your car insurance premium if you bought a car that was completely self driving?