What is the difference between Rigidbody.MovePosition() and transform.position with Lerp?

What is the difference between using Rigidbody.MovePosition() (with interpolation) in FixedUpdate() and adjusting transform.position with deltaTime dependent Lerping in Update()?

I am making a first-person character controller with a kinematic Rigidbody component. The problem I am currently solving is that of a jittering camera. To solve this, one of the methods I could think of is smoothing out the movement via interpolation of some sort. I have come across Rigidbody.MovePosition() and Interpolation settings combo as a way of doing that, however it is still unclear to me exactly how MovePosition() works and and how it is better than custom interpolation with Lerping.

What about transform.rotate() vs Rigidbody.MoveRotation()?