Hmm it makes sense. If gaming and digital content creation are not really in dire need of higher resolution then the only major "segment" is text processing (e.g. coding). In that case it would be understandable if the manufacturers are not pushing hard for this. To be honest I'm not eager to shed thousands of dollars for sharper text when 4k is alright ... but it would be nice. I just thought that the technology would catch up by now and even have time for prices to drop to reasonable levels.
I read somewhere about someone using the Dell 8k monitor for text processing / coding and he/she was claiming that it was a huge improvement switching back to 4k was very very noticeable. So maybe we are not able to distinguish individual pixels but the higher detail and sharpness are noticeable, especially in text. Now, a lot of people would probably claim that text sharpness is not a good use case (after all, you can pretty much do the same thing with lower resolution) but if you are staring at pixels the whole day you might as well make it a better experience. On the plus side, if you are working in the browser / text editor, you don't really care if there is 8k content or stuff like that - just by having the higher resolution, you already benefit from it. What I can say, from my experience, is that the LG monitors I bought a while ago were well worth it (they were about $600 back then, now the prices have dropped significantly).
I guess it's just a matter of time. I'm sure a lot of people would be happy to make the switch if they don't have to sell a kidney in exchange. My totally unverified and amateur prediction would be that we are soon (end of this, beginning of next year) to have higher resolution options, because
1) DP/hdmi standards have caught up to the higher resolutions (and we have video cards supporting them)
2) apple has a 6k display, now everyone wants one ... that doesn't cost the equivalent amount in dollars (ok fine, not everyone, calm down)
3) we already have a lot of options from normal displays, to hdr displays, to different variants of ultra-wide, etc... if a manufacturer wants to stand out - maybe that's the way
4) it really isn't groundbreaking technology at this point