It's not about "where attention and reason doesn't contribute to success", it's about the simple reality that if someone commits to having something staffed "5

It's not about "where attention and reason doesn't contribute to success", it's about the simple reality that if someone commits to having something staffed "5 days a week" or "24/7", then either their costs have risen 20% or the salaries have to fall 20% when the working shifts fall by 20%. That might be acceptable to some business and staff (part time employment is already a thing) but magical productivity improvements aren't always as achievable as certain knowledge work fields. More attentive drivers don't go 20% faster or have 20% more space in their lorries, and for that matter I'm extremely sceptical people would pay 20% more attention to the roads working a four day week than a five day one.