

I’ve used 5K some.
IMO the only ostensible benefit is for computer type stuff. It gives them more headroom to upscale content well, to avoid anti aliasing or blurry, scaled UI rendering, stuff like that. 4:1 rendering (to save power) would be quite viable too.
Another example would be editing workflows, for 1:1 pixel mapping of content while leaving plenty of room for the UI.
But for native content? Like movies?
Pointless, unless you are ridiculously close to a huge display, even if your vision is 20/20. And it’s too expensive to be worth it: I’d rather that money go into other technical aspects, easily.



The bot isn’t really cognizant of its own replies.
…Well, it could be with a postfilter, ranging from sanity checking its own reply, to a tiny separate safety model (of which many exist), to a basic keyword check. But apparently Twitter has no resources for such things.
But the point is this isn’t really the intended design.