Artificially reducing efficiency is of course stupid. However, I think new forms of wealth distribution might be required, because it certainly isn't a given that there will always magically emerge new jobs to replace the old ones.

Of course as an alternative to new forms of wealth distributions, people without jobs can simply starve to death. After a few years, there will again only be people with jobs. (I don't suggest this is a good solution, just that it is one reason there will magically always be jobs for people).