If technology is advancing, why aren’t we working less than 8 hours a day 5 days a week?

Technology is making labor force more productive.

Then cost to produce should decrease.

Then intuitively, labor force should be working less.

Or at least, the price of necessities should decrease allowing labor force to, say, pay off mortgage sooner or retire sooner.

Or have surplus of money to spend on luxury thus increasing overall happiness.

Yet, definition of full-time job is still 8-hours 5-days a week and many fulfill this until the set retirement age.

In US, average hours worked per year per person was 1871 hours in 1990 and 1796 hours in 2024 which is 4% decrease, but birth rate also decreased from 16.7 in 1990 to 12.01 in 2024 a 28% decrease. And I'll roughly relate birthrate to affordability here.