There's nothing magic about it. My point is that in the past it was often the case that building the machines that replaced jobs often created enough new jobs to greatly reduce the net job loss. The number of machines needed was proportional to the number of jobs the machines replaced so it scales.
When it is not new physical machines replacing jobs but rather software, often running on machines the employer already had, you won't get that kind of balancing job creation.
Maybe I’m wrong, and I certainly have no studies backing up my feelings, but not having to work seems like it would be a massive psychological disaster.
Having external reasons to get up in the morning (providing for your family, being apart of some organization, etc) feel really important.
We've spent over 300 years doing the Luddite song and dance. To be clear, I have no problem with Luddites and do not view them negatively, but to imply that this productivity enhancer is magically special in a way no other one was needs some kind of incredibly solid explanation.
edit: as an aside, I do wonder how, if ever, we'll make the transition over to a world where people don't need to work. It seems like every time we think we might be getting closer, the first response is fear.