Comment by n0ot

Using VoiceOver compounds the not responding issue. I don't know how its internals work, but I imagine it tries to keep a view of the window's state--tree of elements, ETC. If the window has a lot going on, VoiceOver can get really sluggish, and I think it must somehow block the underlying app's ability to send/receive events, because you will press VO+right arrow to move to the next element, VO says "Safari/Chrome/Brave" not responding, and if you open up Force Quit, it reflects the same there. Reading a large diff on GitHub flat out doesn't work for me at all. Also, sometimes when navigating certain webpages, VoiceOver will just outright crash. Luckily, it does restart itself (not that pressing CMD+F5 is hard), but then my focus is moved to a completely different part of the page.