I think these sorts of things are very commonly misleading. The Romanian school system I grew up in for example nominally had way more advanced subjects even in middle school, not to mention high school, than what is commonly taught in much of Europe and the USA. For example, we did a solid two-three months of basic group theory in the 10th grade (sophomore year?) - learning about monoids, groups, rings, fields, proving isomorphisms between various structures etc. These were even part of the Bacalaureat, our equivalent of the SAT. A foreign language (almost universally English) is part of the national curriculum in Romania starting from the first year of primary school. When I went through school, we also used to have a set of canonical literary works that we were expected to read and be able to provide literary criticism on during the national exams at the end of middle school without access to the text; for example, the exam you'd take at the end of 8th grade would ask students to write a ~700 word essay on the main character of a particular Romanian novel; or on the themes of a piece of poetry the exam named, but did not reproduce.

However, the number of students who actually ever understand any of this is typically only a small fraction. In particular for the Romanian language exams, despite the theoretically high level of literary knowledge that it tested for, the actual rate of functional illiteracy between students who passed this exam was >20-30%. A huge swath of students either cheated, or simply memorized entire essays by heart, without even understanding what they meant. Of course, some of us actually did learn all of this from an early age - but this was far less typical than looking at the curriculum, exams, and even exam results would have suggested.