Not necessarily. Test taking is a skill in its own right. The PISA test is for example 4 hours long, and students might not have the endurance to stay focused reading text that doesn’t matter and answering questions they don‘t care about for 4 whole hours.

Not being able to focus for 4 hours seems like a bigger problem. But it’s also entirely orthogonal to your distinction of “teaching the test” vs “actually educating”. You can’t teach people to focus for 4 hours.