IT'S NOT ABOUT GETTING TO 120FPS YOU MUPPET!
a 120hz screen with VRR allows developers to target 30fps, 40fps, 50fps, 60fps, 70fps, 80fps and so on and so forth.
it allows for an unlocked framerate without frametime stutters. it allows developers of all kinds of titles to target all kinds of perfomance profiles.
and besides, yes it will come close to 120fps. not sure if you are capable of understanding this, but not every game has the same GPU and CPU demands! BREAKING NEWS I know, but it's indeed true that GTA6 and Cuphead when played on the same hardware will not run at the same framerate