It is absolutely true still, it is especially bad on iOS and the worst when you have a ProMotion device. They did hard lock the max fps to 80fps on scrollable elements on ProMotion devices, which really is telling enough but it doesn't solve the very noticeable jitter either.
I'm writing a game in Flutter. The game has ads, shaders, custom gesture detectors, ... . I can tell you, it is absolutely butter smooth on iOS.
I tried something similar a few years ago and I would have said you're absolutely right. But with the one I'm writing now, it is quite the different experience.