If that is the structure in French schools, then it is quite different than the 1970s, when I spent a year in France as an exchange student.
School was full-time on Mon/Tues/Thurs/Fri, and half a day on Wed and Sat. (Being American, with an aversion to attending school on Sat, I managed to schedule my classes so that I had Sat off.)
I also do not recall any long breaks. Christmas and Easter, maybe, but otherwise, there was at most a day or so off at a time. The school year was longer, too.
As far as academics, the French schools put American schools to shame. I was a good student--I had to be, to be accepted into the highly competitive exchange program--but when I went into French schools, they were so far ahead of me academically that I felt dumb. I could keep up in English class... but otherwise, no. The material they covered in math was stuff that I didn't see until university here in the States.
I only wish I could have had the benefit of a full French education when I was a kid. Still, I managed to go on to a PhD, so I didn't do too badly.
The best thing I read about French elementary schools is that the children in first grade have to memorize a new poem every week. What an amazing concept. Wouldn’t matter if they were little rinky-dink nursery rhymes. Every poem teaches a lot of lessons.
Conversely, I suspect many children here never have to memorize a poem.