Capitalism is designed to optimize production processes, i.e. make production cheaper. That is literally what it does. There are many examples; Just consider how much work it required to harvest wheat or wash clothing 200 years ago. 99% of the population spent most of their time doing these things. Now tractors do most of the harvest, washing machines literally only require a few button presses, etc.

(I just want to add that “work” during the medieval ages was typically not hard work, watch this video: Work - Historia Civilis. It shows how workdays were typically much lighter and shorter during the medieval ages. Note that landlords already existed back then, and they were just as greedy as today. Greed is not a modern invention. So it is neither the landlords nor the greed that causes long hard workdays.)

I think it is “progress” that causes hard work. Let me explain: 1000 years ago, when you were done with the work, you were done. There was literally nothing else to do. There were barely any bridges to be built, maybe a few houses to be built, but that was it. No point working more than what you need to do to survive. Then came the industrial revolution, and people realized that it is possible to build trains, cars, fridges, telephones, smartphones, and all kind of luxury items. Suddenly, when you work longer hours, you can produce more goods. Since people are still greedy (and this is not only the landlords, also the commoners), people want to have nice things. Since you can produce them now if only you put in the work effort, people do in fact put in the work effort, and that’s what caused workdays to get longer and more tedious. It’s literally progress, or the possibility to have nicer things, that makes people work harder to get these things. In other words, hard work will only end when progress ends, in other words, when we stop innovating and having new ideas. Only then will automation eventually catch up and keep the quality of life constant while we don’t have to work anymore.