In France, school is relaxed. It's more about making you an aware citizen than a calculator. The parents always feel the schools are mediocre because they fail all sort of international grading competitions.
Universities are inexistant on the Shanghai Index. You go to class if you want, exams can be compensated by good personal projects (I hated theorical geometry but loved OpenGL so much, that I passed the 3D geometry class with a 10% mark at the exam and a 95% mark at the OpenGL 3D engine semester project that implemented the concept I could not find pleasure in memorizing formally).
Now I have a choice to put my kid in the HK/Chinese system, the French system or the UK/American one, and ... frankly Im so shocked by the lack of focus on kind citizenship, political duty, critical thinking and no alternative to the ever-parent-scaring french "school is not to give you a job, but to give you knowledge" that I still put her in the French system which I used to think was shit.
But well it's not public and some of the things you said on public school apply to France too (unmotivated teachers, often manipulated by unions to think they're so underpaid they have no choice but to interrupt and sacrifice their kids education to fight for their stolen basic rights)
This was the biggest part that got me. I thought university was a place to actually learn things.
It turned out that it's a place for you to rote learn all the required material without any understanding. I saw it firsthand with my friends, who only knew how to follow the steps they'd been taught to solve problems.
Functional isn't what should be aimed for: excellent should be the mark. Right now, the majority still forces their students into thought boxes (e.g if you fail maths at school, you're supposedly balls at engineering for the rest of your life), pretends that spending 12 years memorizing facts is the pinnacle of education, employs unmotivated teachers with below-average salaries, and teaches topics from the last century.
My university experience was simply a continuation of highschool and being treated like a child. Exams we still about memorizing with no focus on understanding, attendance was obligatory, tech was sometimes >20 years old, and so on and so forth.
Even the systems and curriculums within states (!= country) can vary pretty heavily. The bologna reform supposedly made comparing degrees between countries better, but a bachelor in mechanical engineering may mean something entirely different in Poland and Spain.
Better doesn't automatically mean good.