It looks like it does the same thing as
Time.timeScale, only for the Animator. But it works somehow specifically. You need to call each frame for it to work + you can only speed up the animation of the Animator, but not slow it down.
Scaling the playing time of the Animator is easily and clearly carried out through the
Animator.speed, then why do we need
Animator.Update(), which for me does not even understand how it works?