Our monitors don't have 'unlimited' refresh rates, and that is why you don't ever need unlimited FPS. The maximum number of FPS for each monitor is different depending on how much each can support. If your monitor is 60 Hz, having FPS over 60 is useless. Most gamers use 144 Hz monitors for gaming, which means 144 Hz is perfect, but then anything above 60 because things will run smoothly over 60.