It doesn't matter if its cheap, the economy requires monetary exchange. What work are people doing that would balance out the work to build composting systems, infrastructure needs, batteries, solar, wheat, 'wild boar' (protip, there isnt enough without farming, I hunt). All of these things you've stated require a long chain of manufacturing, none of which are free. The systems themselves are incredibly complex and require hard human work.
Can you explain to me how any of this is possible under the constraints you've made. I can only see regression not an evolution or an improvement.
There's a productive capacity of the economy, and there's allocation. Currently we allocate a large portion of the economy to dog bowls shaped like toilets that flush when your dog eats out of it, billy bass singing wall tchotchkies, etc. We need a functional economy to produce a lot of the things you mention, but we can absolutely afford to shift resources away from plastic capitalist garbage.
I've known enough permies that have made it work to know that it's possible to have an off grid lifestyle that's quite decent if you value time and relaxation over material abundance. You talk about regression, but what about the regression of people working 3 jobs, 60 hours a week in shit jobs and barely clearing every month? Those same people could have a hay bale house, composting toilet, a permaculture garden and work 15 hours a week to pay for internet/food you can't grow/farming inputs (limited in permaculture setups).
I'm not doubting that it can be done on the small scale. I just dont think it can be done on any large scale. You kinda skipped over what I stated.
There isnt a way to distribution of shelter, food and storage on the scale required with the collapsing tech tree that will happen when UBI is across the board.
The same factory that creates the plastic extrusions for the dog bowl are the ones that make it for the compost toilet. (Yes, Ive used a real outback dunny), even that has a tech tree that is outside of the basic requirements you've understood.
This doesn't go into the issues that will happen when the tech and delivery tree of things as simple as insulin happen. Every parent I know is going to get back into those three jobs to save their kid, its not even a question.
I have serious concern that the "UBI will work" attitude will be successful, it sounds great short term and if we as a society adopt it, and it fails (it will) we've fucked humanity for the rest of time.
Unless every citizen in every country adopts it, those who maintain their military machine will dominate the rest of the planet so easily it would be finished up in a year.
This passive position is a luxury that certain western countries have.
Can you explain to me how any of this is possible under the constraints you've made. I can only see regression not an evolution or an improvement.