What about the population event-horizon?
Work & capitalism are essentially products of resource competition. Back in the days of hunter gatherers when you'd secured your food, the rest of the day was free to doss around. Work, in the form of agriculture, came about when the population could not easily be sustained from freely-occurring natural resources. And while increasing productivity has been responsible for giving us more stuff, it's also being responsible for giving stuff to more people.
Most population experts seem to agree that the human population is not going to rise forever - in fact that it is peaking around now or in the next few decades. And at the same time our personal consumption of stuff (at least in the Western world) has probably peaked too - the physical stuff that people used to have like books, records, radios, cameras, photographs is all disappearing.
We're never going to get to a point of having an entirely digital economy - we need to eat - but we are going to have an increasingly digital economy. But a digital economy is not resource constrained and can't ultimately function on capitalist lines (as evidenced by streaming fees for musicians) - unless we constrain it artificially. That's where there is potentially a case for a universal income - not in paying people to sit idly by while machines make unwanted shoes.