Capping individual participation does not make new low skill jobs. When you cut all low-skill jobs you are always going to increase the number of people below the cut as not everyone is going to successfully re-train into a job that won't soon be automated. Making new high-skill jobs does not help them.
I don't see a convincing solution other than UBI. Sure, it's untested, and the transition is going to be rough. But capitalism isn't going to stop automating jobs. The jobs are going away and I think the easiest way to prevent the negative effects of having a big chunk of unemployed young men of fighting age. When given a choice between extreme poverty and fighting to overthrow your government, the choice is obvious (Syria for example). When given a choice between a comfortable lifestyle (if you budget well) and fighting to overthrow your government, the choice is obvious.
Part of the reason poverty sucks (in a developed country) is that you have to work long hours for barely enough money and then cook and clean and take care of your kids / elders. If you don't have to work, the effective poverty line drops significantly.
Our society already has the wealth distribution issue, and seems to be moving forward without crumbling. If we can drop 40% of jobs without decreasing overall productivity, I don't see why we have to make something up for the unemployable to do.