- Edited
This is still a thing. I suspect it has to do with the side tab bar, which has to get “rendered in” (just my guess) anytime the user scrolls up enough for the URL bar to be shown.
This becomes an issue with dozens of tabs, or more. Firefox and Safari iOS do not have this issue.
Another aspect of this is severe lag when switching to landscape mode, e.g. to watch a video. I will see the tab side bar until it has completed whatever it needed to do, then disappear, and only then (!) will the video take up the full screen.