Is it possible that the iPhone filters are weaker due to FaceID requirements? I seem to recall that FaceID (and similar systems, like Windows Hello) depend on IR to get a more 3D map of the face, so it'd make sense that they want to be more sensitive in that range.

Laptops aren't generally being used in the same areas as cars though, so you wouldn't expect to see as many cases involving Windows Hello compatible laptops/cameras.

That wouldn't make sense on the back of the phone.

Possibly. Some models of iPhone use LIDAR for AR tooling as the measure app