Who is going to buy all this stuff if they don't have jobs?
And there lies the heart of the problem: purchasing power is coupled to having a job.
As technology marches forward, that coupling has to be let go. Or at least loosened. The majority of the population needs to have some purchasing power even if there's no job for them. Think basic income.
The alternative: (almost) everything automated, production equipment (including robots) in the hands of a few corporations & the billionaires at their top, with the rest of the population jobless / out of money (and in the extreme case: out of housing or food). Great recipe for say, a nice little civil war. As it has been several times in history.
The automation itself isn't a bad thing, it increases productivity so we can have more nice things or do fun stuff more of the time. But the fruits of that increased productivity should be divided somewhat evenly over people. If it ends up in the hands of a few you have a recipe for disaster.