However, people also want to spend more money and have more things / higher standard of living than people had at that time.
I'm curious if you would adjust your own standard of living accordingly, you could finance it with a 15h workweek just fine. But this for sure does not apply to low wage jobs.
While inequality is now clearly on the rise (and it's a big problem), afaik there also have been times in history when it was consistently higher. https://ourworldindata.org/income-inequality seems to have some good charts and context here.