If you only want to test resolution bumps once, use the free Tuner. If you want a set-it-and-forget-it experience, the is vastly superior.
Use thousands of pre-tested cloud profiles tailored for specific games (Quest 2, 3, and Pro).
The answer is system access. Meta does not allow apps in its official store to modify CPU governors or render resolutions. Therefore, you must the Quest Games Optimizer APK using a developer workaround. This "APK" format is the skeleton key that bypasses Meta's consumer restrictions.