The thing is that in the 50,000 years of human invention, we've never had the threat of all blue and white collar jobs being taken over by automation all at roughly the same time, and that is what we would face with an A.I. It's very much an unprecedented situation, but we can get a "feel" for it by looking at the past where things such as the loom, the shipping container, the combine harvester, Factory robots, and the PC have eliminated, or dramatically reduced certain jobs to the point of 90% or more redundancy for those that were engaged in that type of work, and then spread it across the board.
How well is our society going to work if 90+% of the workforce is made redundant over a decade or so? How do we absorb, create new jobs and retain that amount of people in such a short time?
Take a look at the old coal mining towns in the UK and US, the car and steel factory towns in the US, that is the likes of what we would be seeing, but rather than in just a single town, right the way across the world.