I think except for sight reading, while repeating the same music more times in a row, we are mainly practicing technique.
You can build up technique through practicing music, if you do it wisely. Even advanced players won't simply play the whole music several times. They focus on difficult parts and solving issues, which would break down to small mechanical aspects going back to same pure mechanical exercises of the pure exercises practicioners. But there is an important difference when using music passages to practice the mechanics: there is a musical target.