Maan, French don't Know french(?)

(I'm Delf, taking B2 in 4months)Well, actually real French don't know my french and I don't know real french(Yes, this is a cry for help) So, the other day, I asked my French teacher, why and they made french EXAMS that hard and as the talk went on she said : "Exactly, I've seen cases like that. There are french that can't pass the exams...". Then, I'm like, "Wth is going on here? Why would someone make exams for a language without even consulting the country of the language." Is this really true? French people don't know their language(that much)? So I'm more French than full blooded French rn? And the worst part is that they're making it worse, and they do nothing after any complains they receive.

EDIT: Just to be clear, I speak about the exam, not the people. I meant no offense, and if there was any taken, I apologize sincerely.