The problem is that we have a (figurative) glut of job openings for neurosurgeons and a severe shortage of neurosurgeons. The answer not to make the existing neurosurgeons work fewer hours; they are serving a valuable, irreplaceable (in an availability sense) function every hour they work. You can't give a lawyer, janitor, and accountant a crash course in neurosurgery, split the job between them, and expect a comparable result in the aggregate even though you created more jobs. At some point we will have to come to terms with the idea of decoupling a job from a decent life in the same way that jobs are being decoupled from economic growth.
The limit of this scenario is interesting as a hypothetical. When we get to the point where only 5% of the population is employable and they are all employed with very valuable skills that are in extremely short supply by definition, how are those people treated once the vast majority of the population depends on their continued work while 95% of the population no longer needs to work and is not usefully employable in any case? Can the 95% not working force the 5% to work long hours because there is a desperate need for their skills and talents which are not easily replaceable? It is a different political dynamic than when the majority of the population is contributing to the economy that supports society.