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.