To be fair, 60Hz to 75Hz is barely noticeable even by those who are used to notice these things. If you can’t tell the difference, it’s understandable.

Then, the bigger the screen, the more noticeable high refresh rate is, because it covers more of your field of vision. So in a small iPhone screen it’s not easy for everyone to notice (and then there is the fact that iPhones rarely go to 120Hz anyway which is an absolute mess by itself but that’s another topic, so your 15 Pro probably rarely goes above a noticeable Hz change anyway).

However, if you get a 144Hz or above, 24" and above monitor, you will IMMEDIATELY see the difference against your 60Hz monitor. Even moving the mouse feels more responsive and accurate. Makes targeting stuff with your mouse easier. Reading text while scrolling is possible also. It unlocks a new world, it’s not only for gaming. Casual and work use also benefit a lot from high refresh rates.