but who will have money to buy it?
There will be new toys and bobbles needing to be produced to keep the few elite super-rich amused.
Also, up to a third of the general population will still have jobs.
Fast-food, prostitutes, maids, butlers, drug-dealers, gardeners, gated-community security, man-servants.
And the military. It will always cheaper to send young underclass kids to go fight the corporate-wars than develop the technology to completely replace them. I doubt you'll see Elon Musk's son sporting an Infantry Badge. He'll probably develop mysterious bone-spurs at the convenient time.
Besides, It keeps them busy and distracted and periodically culls the herd. It's not good to have too many military age males sitting around unemployed and hungry thinking about their lack of a future.
https://ratical.org/ratville/CAH/warisaracket.html