Edit: the answer here is that some jobs are still necessary and the ruling class hasn't found yet a way to motivate people to carry out those necessary jobs, if not by keeping everyone on the edge of starvation. If food and habitation were to become free, people would just stop being the useful tools they are supposed to be. That's why ubi is never going to take off.
Edit 2: Am i been downvoted by the ruling class? Actually, maybe it's because i said i don't think the ubi is going to stick. If that's the reason, I want to clarify that i believe ubi is going to be necessary in the long term, though I also believe it's just a piece of the puzzle. Another piece would be limiting resource usage by accounting for externalities through a system like carbon credits, but with more types of resources (not just co2) and for individuals. It should be a system that lets the normal person live almost normally, but stops the rich from doing the fuck they want just because they have money. At least they would have to buy credits from other people and pay them if they can get them.
I'd like to see someone try a UBI system that was genuinely universal. Literally everyone gets it, employed or not, regardless of income level, but at the same time minimum wage is removed because your living expenses are already ostensibly covered. So if a business can get someone to come in for $1/hour, or even for free, great. All wages just become "gravy" if someone wants luxuries above and beyond basic living expenses.
Under such a system I'd be interested to see how much what are currently minimum wage jobs would need to offer on top of UBI to get people in the door. I could absolutely see things like hobby shops employing people for pennies who'd be happy to be there just due to interest/passion in the subject of their work. Conversely I could see the wages for dreary or abuse prone jobs like gas station attendant or fast food cashier going up because no one in their right mind would want to do it for a pittance if their basic needs are already covered.
This is A very interesting thought. I think you might be not to wrong with your assumptions about jobs. I also would really like to see this in practice.
It is really simple if you eliminate social welfare and make UBI part of taxes, you free up a lot of money. Everyone gets $35 000 a year or does not pay any tax on their first $35k.
This creates a system that is already less expensive to operate than the current mess and injects a lot of money into an economy.
The ruling class hate this idea because if people are not jammed into a corner living paycheck to paycheck or worse, they tend to quit their jobs where their employer was abusing them and get a better education. Or say fuck you to your employer and live poor until you get a new job.
It's paradoxical, though, because anti-labour tactics make those jobs paid so badly that it is not worth automating e.g. trash collection, packet delivery, cleaning staff.