Who is saying it adds missing frames? In fact that is exactly why can be useful, because it doesn't repeat frames.Vrr is never going to add missing frames.
It's good on pc as fps is generally north of 60 fps.
Instead of a game repeating frames to fill in the blanks left by a framerate below 60 it syncs the gpu to the display so 48fps is out putting at 48htz so less perceived stuttering, no tearing, less latency.
It going to be a useful tool no matter where its used, and its only going to become more and more prevalent. TVs with hdmi2.1 spec will have it by default and PS5 will have it soon enough.