The possibility that it won't merits consideration. It's entirely possible that new industries will spring up, but it would be dangerous to rely on that and plan as if it were certain. Even the "long tail" that people predicted for artists to make a living in a widely-connected economy has thus far largely failed to materialize.

The fact that I can't imagine it is no proof that it won't happen, of course. But I feel that we've gotten lucky in the past, and I hate depending on my luck.

i guess if you take this idea to its logical conclusion, we will end up in a post-scarcity economy where nobody "needs" to work, yet all their needs are met. So far, it's unclear whether this outcome will occur, and I do agree it's unclear what the outcomes of the information revolution will be, in terms of overall economic comfort of individuals.

This doesn't seem to be guaranteed by any law of economics, though. Despite the massive economic growth since the 19th century, the absolute number of job openings for horses has decreased substantially.

> but long term, the economy grows, and adds many more categories of jobs.

Perhaps, but if history is any guide, that "long term" will span over multiple generations. That is of no help to those being hurt now.

The logic seems to be:

B followed A once before, therefore B always follows A.