I made it to the end!
They think we'll botch retraining.
While the pace of technological change is arguably accelerating, we have seen no evidence yet that the rate of human adaptation to jarring economic dislocations has improved. If anything, the experience of the two recent US recessions points in the opposite direction—an aging labor force is becoming less able to learn new skills and find work. The demographic outlook for the next decades suggests that the labor force's speed of adjustment to disruptions might actually worsen.
Our base-case scenario forecasts an acute shortage of highly skilled, high-income workers in the 2020s as investment in automation technologies takes off. Over time, workers will acquire new skills and migrate toward the jobs in demand. However, shifts of this nature take a considerable amount of time.