How does needing raw materials create employment for the rest of the population? If everything is mechanized, then raw materials come from those who own mines/wells, and the extraction is done by robot labor. That doesn't involve very many people.
It doesn't create employment for the rest of the humans. In this scenario, most humans are unemployed - and probably rather poor - due to the hypothesised lack of "substantial taxation" and government handouts. The throughput of the economy arises essentially from the efforts of the machines.
The question that the ideas are supposed to be in response to is:
Here are links to some proposed ideas that you should vote for, assuming you agree with them. You do have to register to vote, but the email confirmation arrives right away and it shouldn't take much more than two minutes of your time altogether. Why should you do this? The top voted ideas from this request for ideas will be seen by some of the top policy recommendation makers in the USA. They probably won't do anything like immediately convene a presidential panel on AGI, but we are letting them know that these things are really important.
Research the primary cause of degenerative diseases: aging / biological senescence
Explore proposals for sustaining the economy despite ubiquitous automation
Establish a Permanent Panel or Program to Address Global Catastrophic Risks, Including AGI
Does anyone have any other ideas? Feel free to submit them directly to ideascale, but it may be a better idea to first post them in the comments of this post for discussion.