Standardized tests measure students' ability to take standardized tests. This loosely correlates with their knowledge and understanding of the subject matter, and correlates more tightly with knowledge of test-taking strategies specific to the test they are taking. So no, most of what students need to know to pass the tests is not useful real-world knowledge.

To put it another way, knowing the material is not the easiest way to pass the test, so even if the test nominally evaluates useful real-world knowledge, a high score won't guarantee that a student actually possesses that knowledge.