You are really clueles aren't you?
France enacted the 35 hours a week policy because data showed that production would go up. And indeed it went up. Because employees are less tired they work better. Here, in NC, I have student working 50 hours a week, except they don't do shit for 20 of these hours becasue they are exhausted. I keep pushing them going home and getting some rest.
Things are expensive in France for two reason. The first one is the cost of living which drives salaries up (otherwise people can not afford rent) and prices up (otherwise the store can not pay its rent).
The second one is the massive unemployment rate. There are 43 million people between 15 and 64, but only 27 millions of these people are actually working. There is an official unemployement rate of 10% because 13 million of these people are not counted as active, mostly because they have been pushed to change their official status. But the real unemployement rate is closer to the 30%.
Now I agree that conservative labor laws are part of that problem. But working time is definitively not the issue. One of the problem is the difficulty to get rid of an employee hired under an "undefined length contract" (CDI). It is so difficult to get rid of them that businesses are very reluctant to employing anybody. This drove short term contracts and lack of retention of skills in businesses.