5K 27” looks usefully better than 4K 27” to my middle aged eyes.

I’d prefer that to not be so, because 5K panels are so much more expensive. But in a side by side comparison it’s very obvious.

But the market has spoken: a quality 4K display is very good, certainly good enough, and the value for money is great.

I’m ok with spending more on a better display that I spend so much time with. The cost per use-hour is still very, very low.

It's not just that: bandwidth needed to drive things above 4k or 5k is already over the limits of HDMI 2.0 (and 2.1 without all the extensions). DisplayPort is a bit better with 1.4 already having enough bandwidth for 8k30Hz or 4k at 120Hz or 8k60Hz with DSC.

When considering a single-cable solution like Thunderbolt or USB-C with DP altmode, if you are not going with TB5, you will either use all bandwidth for video with only USB2.0 HID interfaces, or halve the video bandwidth to keep 2 signal lanes for USB 3.x.

(I am currently trying to figure out how can I run my X1 Carbon gen 13 with my 8k TV from Linux without an eGPU, so deep in the trenches of color spaces, EDID tables and such as I only got it to put out 6k to the TV :/)

We're approaching that point but are not there yet