In systems where the put students on a university or vocational track, they usually make the determination at around age 14. The schooling up until that part is the same, officially, although they might track by ability in some cases.
If the system is going to work, then the students would indeed be forced onto a certain track; otherwise, you’ll have the same situation that we have now where students who can’t/won’t keep up will be in the same classrooms as the students who can/want to learn.
Yes, they should have the ability to shift tracks even before 18 by having some kind of exam, but if they don’t pass, they would still be forced onto the vocational track. That’s why a lot of people would probably object.
