Why does my mouse feel bad until i have more than 100 fps?

Because the game is badly coded and input is tied to refresh rate. Game can poll input faster than it renders its frames, but most devs are lazy (especially console devs and their console ports, because they don't have to cater to different setups) and just lock whole game loop into single target framerate.

When people say they want 60fps, they mean they want game to render at 60 fps, so that motion is smooth. If the game needs responsive input, it should be polled at higher framerate, and the rendering interpolated based on that.