If there is one thing that would make the iPhone 11 feel unstoppable, it would be a 90 Hz screen.
The iPhone 11 has a 60 Hz screen, which is fine. However, 90 Hz screens are faster and smoother and have a significant impact on the quality of the phone. This is not a necessity, but with OnePlus, Razer and Asus phones having 90Hz screens, Apple's iPhones (and other big-name phones like Samsung) are beginning to look outdated despite the fancy design and fancy technology.
But I can see why Apple has not adopted the 90 Hz screen. Screens with higher refresh rates may consume more battery. Apple offers better battery life for the new iPhone 11 phones, which appeals to more people on a 90 Hz screen, especially if the current 60 Hz screen is good enough.
For reference, "Hz" refers to "update rate". The higher the Hz number, the higher the refresh rate. This means that a screen can display more pictures per second. With a higher refresh rate and more frames per second, animations like opening and closing apps and swiping between the operating system and apps are smoother. It has a surprisingly large impact on how high a device feels.