Why my CADisplayLink runs at low framerate, but UIScrollView doesn't?

I have a tiny iOS app project set up.

I instantiate a CADisplayLink and then log the time that passes between its calls to target-action. This is on an iPhone 15 Pro, so 120 hertz. However, I am observing that in user space, the actual tick rate of my target-action being called is actually fluctuating around 70-80 hertz.

But then, I instantiate a UIScrollView and give it a delegate. In the delegate I am observing that scrollViewDidScroll gets called with the correct 120 hz. And if I set a breakpoint inside scrollViewDidScroll, I can see that this is called from a CADisplayLink handler inside UIScrollView. How comes they can have 120hz, and I don't?

Of course, I did set UIScreen.maximumFramesPerSecond to preferredFramerateRange, minimum, maximum and preferred. Also, I don no virtually no work in the handler - I am just setting UIView.transform = CGAffineTransform(translationY: 100).

Also, my info.plist does indeed contain <key>CADisableMinimumFrameDurationOnPhone</key><true/>