The same thing that happened to stable boys, bank tellers and farmers. In 1870 53% of the labour force were farmers, by 1970 that was 4.6% (https://www.agclassroom.org/gan/timeline/farmers_land.htm). If you told someone in 1870s that 50% of the labour force will be changing their job, they would have a similar reaction.
Granted the speed with which changes are occurring now is much more rapid; if we consider the largest number of people affected in the smallest period of time, it's probably self-driving cars & trucks that will make the greatest impact.
Driving or making pizza isn't exactly high-skill work (in terms of time taken on training), hopefully the transition happens slow enough for these people to retrain for other work.
Granted the speed with which changes are occurring now is much more rapid; if we consider the largest number of people affected in the smallest period of time, it's probably self-driving cars & trucks that will make the greatest impact.
Driving or making pizza isn't exactly high-skill work (in terms of time taken on training), hopefully the transition happens slow enough for these people to retrain for other work.