I think there's a fundamental error in assuming that lack of productive employment among much of the population necessarilyequals poverty.
I actually think that the scenario where technology grows our collective productivity so well that few of us have marginally productive capability is a very good thing for the wealth of the poor--at least in the moderately democratic first world.
Why? Because it means there's way more wealth in general. Yes, in an autocracy the unproductive could be left to starve... but in any slight democracy there will be constant political work being done to share the wealth.
Much of that work will be ideological and identity-based cover for what is effectively a clumsy, haphazard socialism. Hence you have the anti-government Nevada racist rancher guy who happily takes government land subsidy checks and advocated for massive government seizure of labor wealth and private wealth to pay for a security state.
Isn't this the old argument for supply-side, or trickle-down, economics? Not quite. That argument was an argument for redirecting wealth away from the welfare state and towards the already wealthy, with the justification that this would indirectly serve the working class even better than direct subsidies.
My argument is that overall productivity growth, which expands the whole pie, will make up for the reduction in wealth of the working class and poor due to replacement of unskilled and semi-skilled labor due to computerization. This process will be painful and problematic, but not apocalyptic.
We'll be amusing ourselves to death, but we won't be starving to death. At least in the first world, where there is a practical cost to too much poverty.