With a significant portion of mass consumption missing, wealth would start to erode. Stable inequality could grow up to a certain point, but not without adverse effects on investments. You can only sustain wealth without consumers in an absolutely totalitarian society, but even there it would lead to a catastrophic societal collapse sooner or later.

I think this is a dead angle for a lot of AI experts. That sudden bump in efficiency might ruin large parts of the markets businesseses are built upon.