I would say that it is demonstrably not true in many EU countries. Maybe "non personalisation" is the tendency of lazy teachers, but I remember pretty well how my math teachers repeated the same subject thrice: the first time describing its core in an abstract way, the second time with concrete examples (apples and pears) and the third time in very little incremental steps. The first explanation was for naturally able math learner, the second for those how needed practical examples and the third for less able pupils. Some of us complained about the fact that it was a boring way to teach (and you know how horrible bored kids can be in the class) but I'd say it was worth it to have all my classmates learning more or less at the same pace with nobody left behind.
Actually, I complain more about the fact that we had to change math teachers so many times because of educational reforms and budget cuts/reorganizations.