The idea that people before us lived worse lives is one often used to obscure the clinical nature of standards we attribute to quality of life such as lifespan, infant mortality, food security, and housing. This is because it allows corporations to trivialize the impact of doubling the workload by normalizing the 40 hour work week and housework and child care, what used to be two people's worth of work, into one.
Are we living 'better' lives? On paper, sure. Are we living happier lives? That's hard to say.
We don't have to romanticize the present either.
People still work 10-12 hours a week except they still have to buy their own groceries, cook food, clean the house, take care of their kids, and every other logistic that goes into housework. The idea that people always worked more and had less leisurely time in the past is one often used to downplay the impact of unpaid female domestic labor in the past to justify to expecting it of every person in the present.
Moreover, preindustrial workers only worked 1440 hours annually compared to the modern standard of 2080 hours. And that does not even include unpaid domestic labor.
Yes, it's great to have all the social advances and modern comforts that we do. But humans are not machines where by indefinitely increase our quality of life we can expect an indefinite increase in hours worked. Just because we have smartphones, AC, cars, and whatever modern luxury you want to include, it doesn't mean that suddenly we can work 12 hours a day every day and mentally stay sane.