Capitalism was also people working in the fields and trading their produce, after paying their tax to their lord, not unlike to our income tax.
There are definitely many trends that led us to work more and more. There are increasingly more and more people in the few places people with ambitions want to live in. That's more competition which gradually drives the cost down. If the wage is already low enough that it's unreasonable for someone to live on it, the working hours will go up.
The real modern culprit in my opinion is the mandatory education system which indoctrinate kids to become employees for life instead of helping them find a place in society and in the market by providing value as a small business.
With less employees around wages would go up, with more small businesses the capital would be spread more and not concentrated in the hands of a few.
It's not hard to understand who is benefitting from this system: whoever owns capital and need workers.
I'm sure there is plenty of overlap with people controlling the media and telling people what to think and want - and people in the government approving laws.