This is sadly true. And I’m not talking about the adaptive nature of the ProMotion display.
For all the iPhone 13 Pro/Pro Max users take that test:
Go to the Settings app, start scrolling up and down. It is smooth right? Okay now open Control Center and start screen recording (if you don’t have the screen recording button on the control center, add it for the test). Now before the countdown finishes, close control center and start the scrolling again.
You will notice that until the screen recording starts, the scrolling is “smooth”, but as soon as the countdown finishes and the screen recording starts, the scrolling is noticeably smoother!
You can experience the same thing when swiping between home screen pages, when scrolling on Instagram or Facebook, Safari etc.
For some reason, Apple is limiting the maximum refresh rate of the display to lower than 120Hz (maybe 90-100Hz) and when you recording the screen, the limit unlocks the full 120Hz!
Fun fact: Twitter seems to go up to 120Hz all the time, even without screen recording! And that’s why for months now I have noticed that Twitter app has smoother scrolling than any other app like Instagram, Facebook, YouTube etc!
So if Twitter somehow is forcing the display to go up to 120Hz, why other apps don’t do it? And why even Apple's own apps don’t?!
I’m very disappointed…
Also I don’t now if that’s the case for iPhone 14 Pro models too.
I’m running iOS 16.3
Edit: Twitter may have done that “CADisplayLink” thing you can read bellow, to go up to true 120Hz, as Apple provide instructions to developers.
https://developer.apple.com/documentation/quartzcore/optimizing_promotion_refresh_rates_for_iphone_13_pro_and_ipad_pro
Videos
Basically all the iPhone base and pro model that I've seen from my friends and family massively slows down after 1/2 years of use, but the iPhone 13 pro (and the next ones obviously) seems immune to that and it feels snappy as it was when it launched. I guess the reason is the 120hz display since physically decrease the input delay and the response of you're touch. All the 60hz iPhone however have this thing where after some time they start to feel weak and the fps decrease, it's almost they run at 40/50hz and there are slowdown here and there.
It surprises me that the iPhone 13 pro is maybe the only iPhone with the performance to longevity ratio higher among all iPhone, maybe because the display prevent it from being cluttered?