No, I don't think if Op meant loading but scrolling over a long page like after opened a thread, you want to scroll through. It sometimes behaves this kind of hanging or slow going unless you've to scroll/swipe the page forcefully. However, loading goes smoothly.
I talk from experience which was shared here few months ago https://bitcointalk.org/index.php?topic=5501072.msg64256087#msg64256087.
The obvious thing there's that I don't experience this if scrolling from down to top but when scrolls up to down. Although the performance doesn't occur consistently but at most.
So if I want to scroll freely, I take from the bottom. Like said, it happens most when the page is lengthy.
I either don't think it's from the device browser because other browsers acts the same but I'll agree with you that it could be from the device capacity probably the mobiles touch screen swipe since it doesn't happen on the system with the mouse. My system isn't one of those screen touch though to test run if it'd be a case of device capacity or just the screen swipe barrier on the long pages.
Moreover it doesn't occur when using other websites but only bitcointalk platform.