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.
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.
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.
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.
