Techno-optimism is the domain of people who're confident that they'll be part of the managerial class that gets alerted when other workers are going over their bathroom break allotments.
Has the last 70 years of productivity increases led to a reduction in weekly work hours? No.
Some jobs will be automated away. Good thing. Braindead stuff that a machine can do should be done by a machine. Doesn't mean we'll all soon be just picking our noses. There will be other work to be done, and if unregulated capitalism has its say then it can easily lead to even more worker exploitation.
Of course, the effects aren't equally distributed across all countries. For example, annual work hours per worker have almost halved in Germany since 1950, but only seen a more modest decrease in the US. So political factors still play a role in how the benefits of increased productivity are used by society.
But it's a strong effect. And those numbers don't even consider other factors such as how increased life expectancy combined with mostly unchanged retirement age, and being older when we first start working, give people an extra decade or two of not being part of the workforce at all.
The 40-hour workweek was introduced in Germany in the mid-1960s. 60 years later, it's still standard. A few 39-, 38- or 37.5-hour weeks here and there, but even those are by and large 40-hour weeks.
The number of vacation week and public holidays has increased, which explains the majority of the difference in "annual work hours".
The 10x in productivity is in no way reflected by the number of work hours.
Hence why I can't stand such techno-optmism, apparently most folks live in an ideal world free of economics.