The idea tends to be repeated due to concerns with displacement of human labor. People need money to purchase or rent housing, buy food, clothing, etc, which we effectively mandate (even clothing is essentially mandated). If that model of society breaks down, you no longer have a functional society. This could result in any number of things, but it certainly doesn't work to assume that people will disappear if they can't find work.
Their suggestions are basically one abstract model that has come up. Since it's not a real consideration for any government that I know of today, they wouldn't have implementation details available. I see it more as recognition of a potential future problem that we will most likely have to address in some manner, probably within my own lifetime.
Keep in mind that their suggestions might sound dysfunctional, but they are most likely concerned that what we have today will stop working.
Universal Basic Income is actually already being tested in Finland, and there may be a trial in Ontario, Canada soon as well. Some form of the idea has been tossed around for over 40 years, but nobody has had the courage to really give it an honest try (nor has there been any urgency). Partisan politics haven't helped either, though Wikipedia seems to suggest that the conservative side of the spectrum is starting to warm up to the idea (my experience is that the loudest proponents are at the far left).
Part of the theory is that everyone is eligible, so there is no means test. It would free people to choose what they want to do - if they choose to work, then clearly they would make more on top of the UBI, and would have more to spend on whatever they choose. On the other hand, the administrative costs of running welfare, etc would disappear. Taxes would likely have to rise a bit, though it isn't clear how much (estimates vary, and frankly, I don't know if I trust any of them, as nobody seems to account for secondary effects).
There is a decent (though incomplete) description of the concept on Wikipedia:
https://en.wikipedia.org/wiki/Basic_income
The key is that, at some point soon, we need to get our heads around the idea that the current model won't keep working. Whatever form that a new system takes, it's likely going to be a painful transition.
EDIT: Sorry to go so far off topic....just wanted to correct one little comment....