It's good for ranking, which unfortunately will never go away (though could become more granular), and much better than standardized tests. And ensures that some students don't miss access to subjects and resources that others have because they're in different schools.

There would still be the ability for students to choose their own subjects, focus more/less on certain subjects, learn different concepts within subjects, etc. And a lot of niche subjects and branches. Like it would be an incredibly massive curriculum, especially since you are designing one for >1million students. By "standard and universal" I mean that every student gets the same resources.