I work construction and would love this, but our issue would be customers thinking we're "slacking" because in a month long job we're taking three day weekends every week.

Compound this with employers who don't value productivity over "time put in", and I genuinely think this won't happen until it's either forced or the current generation of senior management are ousted via retirement/death (as most seem to work until very close to the latter).

I think the older generation is so stuck in its mindset that it's going to take a cataclysmic shift for them to realise they've been stupid for decades, and it's the younger generations that are dragged along with it because they're yet to be the ones in control.

I have done that for a while and, if you have a commute, there is no time left for anything else during those 4 days. It may be a nice option sometimes, but it's not viable for people with other obligations during the week.

i work 4 10's in a machine shop currently. maybe being a machinist is different from programming, but you can't do anything for those 4 days. you just won't be productive after work, you'll be spent. then you spend your first day of the weekend recovering from the lack of sleep during the 4 days, because a longer workday usually means you get up earlier, rather than staying later.