Does it make sense from an economics standpoint? Perhaps not. But there are benefits to society as a whole. Quite often the people doing those sorts of jobs are getting on in life, if having that job means the person can stay active that could represent a few additional years where they won't be a burden on the health system.

Honestly, giving people these unproductive jobs seems to me like a way of giving out UBI without people even realising it. Because at the end of the day, these jobs are just UBI. They don't add much to the economy.

It promotes a better culture. I would support this system over USA's welfare.

You seem to be misunderstanding what UBI is. This sounds more like a job guarantee, which is the opposite of UBI. The main point of UBI is to make sure nobody can ever be pressured into accepting such a job.

Those jobs hardly add any value to society (let alone economy). If you just hand out money instead, some people might find something more useful to do, or at least be better off for themselves. See also David Graeber's essay "On the Phenomenon of Bullshit Jobs".

Why is it unsustainable? The money they take home gets spent thus supporting other people.

The overhead of employing properly compensated people instead of signage and traffic cones is fairly high, while the work they do is not necessary in any meaningful sense. Which is moot anyway as apparently these folks are paid a pittance.

The alternative is to pay people for doing nothing, like many EU countries do. In the end it's not cheaper.

The US provides EU-level social safety net benefits (healthcare, housing) to the lower classes—via employment in the military, which is in part a stealth jobs program that both major political parties support paying for.

We provide a jobs program for white-collar folks through our excessively-large and exceptionally expensive healthcare system. We pay for whole categories of jobs that don't need to exist and are only adding costs. A double-digit percentage of our healthcare costs are a white-collar jobs program paying people to do nothing useful whatsoever, and we spend a lot on healthcare so even 10% makes it a fairly big program.

That’s not really a safety net, because not everybody is physically fit to join the military.

Yeah, I'm aware. It's a really sick way to give working-poor families access to universal healthcare, housing, and free education, which other OECD states mostly manage to do without that. But, it's what we've got.

There are similar measures in many EU countries. For example hiring unemployed people to help kids pass particularly busy streets near primary schools.

https://d-pt.ppstatic.pl/k/r/1/6c/83/5b7d5e3b2b9de_p.jpg?153...

The scale is different. In Japan those jobs can be seen everywhere.

That's called welfare, which has an advantage of not masking unemployment. (but to be fair am unsure if people doing traffic cone jobs in Japan are considered employed)

Anyhow my point is it has little to do with system redundancy.

Welfare / UBI ignores that one of the realities of the human condition is that we are social creatures that have a desire for purpose and utility to those around us, and having that purposes in a society that recognizes us helps give us dignity and a place in society.

It's not important that all jobs are high value, it is important that we as a society have a way to create and recognize purpose for individuals to support their mental and personal wellbeing. While welfare / UBI may ensure they have basic needs met to sustain life, it does nothing to support their mental and personal wellbeing, which is why these systems often results in the creation of delinquent behaviors that are mostly absent in a system like that in Japan.

It may be the the same economically, but socially it is much better to have someone doing an "unnecessary" job that is recognize as valued by society vs simply collecting a check.

This is why I support forcing the idle rich to work retail or construction. Otherwise their mental well-being will be at risk.

Standing there in place of a traffic cone is not much of a dignity IMO, but it certainly could be cultural.

There's definitely a cultural element. I made the point that these jobs must be recognized as valuable by society for a reason.

You say they're standing there in place of a traffic cone, Japanese society instead says that they're there to provide a friendly face ensuring safety of passersby around the dangers of construction work. A traffic cone cannot assist someone who has trouble walking to traverse rough ground because of the work being done. A traffic cone doesn't smile or acknowledge your presence.

That sociocultural element is what has value, and as long as it has value, the job is valuable.