Human cognitive abilities follow a normal distribution. Some low-skilled laborers never had an opportunity to reach their potential, others lack the capacity to perform higher skill jobs... and some people are incapable of even "low-skill" labor.
Is automation maintaining or reducing the number of jobs for less capable people? Are we slowly raising the unemployable-threshold?
Those are good questions. Our challenge becomes ensuring that people are capable. How many of those displaced workers are less capable because of something intrinsic (some mental defect or insufficiency), and how many just need to be trained? I'm not sure if we'll ever reach a point where the "average" person is unemployable, but we can imagine a future where that is the case. But there's such little genetic variation within humanity that it seems likely that our education system could be made much more rigorous and suitable to ensure that everyone comes out of it at a very high level of capability.
The companies will evolve or die as they always have if their customer base disappears.