[ben_w]

The “why” is groupthink, at least if the proponents’ claims are correct.

For the “how”, from l what I’ve been hearing, actual productivity follows a curve analogous to the Laffer curve for taxes, where 40 hours weeks is only the most effective weekly rate for manufacturing jobs in particular, while it’s probably more like 20-30 for intellectually focused work.

I have no idea what the “best” might be for e.g. baristas or bank tellers, where it’s important to have someone physically present even if there’s no actual customer at any given moment.