5k and color accuracy are baseline features for me, and I assume for many ASD buyers. If 1440 resolution was good enough for me, I wouldn't own an ASD. I have an LG 4 right next to my ASD and the picture is noticeably not as good.
It has taken years to have any real competition in the 5k monitor space, and even now there aren't a lot of options.
re: 5k
The problem is somewhat about macOS and how poorly it handles non integer scaling.
All my back and forth with Windows really highlighted for me how great 4k already is. We don't actually need more pixels to have things look amazing, it's just that macOS makes things look less good than they should/could if it's not exactly 2x scaling.