It's true that even with 120Hz display, Android animation still sucks because they're poorly designed and unintuitive, but It has nothing to do with the fact that 120Hz feels much better than 60, and iOS 14 couldn't even maintain 60.
And I'm quite sure that this is not a hardware issue of my device, because I've noticed the same kind of lag on every exhibition unit in the Apple Store.
Fun fact: according to my test at the Apple Store, iPhone XR/11/SE feels smoother than all OLED iPhones, and iPhone 12 mini feels smoother than iPhone 12 and iPhone 12 Pro. iPhone 12 Pro Max is the worst among all iPhones. If i still had my Rogphone 3 or N20U i could definitely see the difference...