So why mass-surveil Apple computer users this way? My understanding is the only thing exclusive to Apple systems is developing Apple apps. But anything relate

So why mass-surveil Apple computer users this way? My understanding is the only thing exclusive to Apple systems is developing Apple apps. But anything related on a platform like iOS is already going to be public knowledge. Also the latest Mac hardware seems to go through great pains to make sure the primary storage device is both encrypted, unrecoverable if keys are unknown (T2 security chip), and non-removable (SSD soldered to board). So why would they make this back door for surveillance?