This is a cop-out - the entire "people will find other things to do" argument is a total cop-out.
Yes, in aggregate, over long timespans (read: multiple generations), people will figure out other things to do. But as we've seen from the automation of manufacturing jobs in the US, a huge number of people haven't retrained, nor have magical jobs "we couldn't even imagine" erupted en masse to absorb a chronically un- or under-employed work force.
I submit that the oversimplified notion that people who lose their jobs to technology will be fine and find something else to do is mainly a device to make people like us feel better - it isn't a notion that actually helps the displaced.
Yes, in aggregate, over long timespans (read: multiple generations), people will figure out other things to do. But as we've seen from the automation of manufacturing jobs in the US, a huge number of people haven't retrained, nor have magical jobs "we couldn't even imagine" erupted en masse to absorb a chronically un- or under-employed work force.
I submit that the oversimplified notion that people who lose their jobs to technology will be fine and find something else to do is mainly a device to make people like us feel better - it isn't a notion that actually helps the displaced.