That's trivially false. Ancient people were always working, and we can see this in people who maintain primative lifestyles.

Take bread.

You start the oven at 4am. By 5am it is hot enough for your meats. By 7am extinguish, by 8am start your bread and go until 6-7pm. Now you get to start your dough for tomorrow, typically working until 11pm.

Historically bakers were known to sleep in flour hoppers as they were spared some of the heat of the ovens.

Ancient people _always_ worked. There was no leisure weekends, no afternoons off.

To me it sounds like you already partially contradicted yourself. Bakers sleeping while at work? That would never fly today even if you had literally nothing to do except wait for bread to rise.

Their hours away from home may be similar in many cases, but that doesn't mean they had as high of a workload or had to work as fast as the modern equivalent. Most of them were working for themselves, and set their own pace and rules. And working for yourself is a HUGE perk and often many people's dream scenario. Want to drink beer all day while you chop wood? Sure. Want to sing baudy ballads while you patch your roof? Go ahead. Hurt your wrist while pulling weeds or managing your copice? Go take an immediate break or maybe just come back the next day. And because 90% of the population did that, those expectations carried over into many other jobs because anyone could walk away and find some farm they could work on instead if they really wanted.

This is easily proven incorrect.

Ancient Rome worked on an 8 day workweek, and traditionally the 8th day was a rest day.

Ancient Greeks didn't have weekly days off... but they had up to 120 festivals a year where shops and businesses would be shut down.