Apple Releases iOS 16.2 Beta to Developers which has fixed animation and fluidity problemsProMotion 120Hz screen of the iPhone 13 Pro, 14 Pro as well
iOS 16.2 Beta Fixes ProMotion 120Hz Screen Smoothness
Previously, users of the iPhone 13 Pro, 13 Pro Max, 14 Pro, 14 Pro Max encountered problems with the ProMotion screen twitching and being slow in use because sometimes the screen did not adjust the refresh rate to 120Hz.
Apple released iOS 16.1 to users to update to fix this problem, but in iOS 16.2 Beta has improved the smoothness even better. It fixes a slow, stuttering issue that developers and iOS 16.2 beta testers found improved the smoothness of ProMotion 120Hz on iPhones.
As of now, iOS 16.2 is still a beta version. It is expected to release an update in mid-December.
source : https://www.macrumors.com/2022/11/17/latest-ios-16-2-beta-stuttering-animations/