It's not 4k, it's that new technology is "better" - higher contrast ratios, whiter whites, blacker blacks, etc. I have a 1080p IPS monitor that makes my old monitors look "yellow" by comparison, and that's at
25% brightness, and the 4k monitor makes the IPS monitor look yellow.What I did was keep the same DPI as I upgraded - so my 4k monitor is about 40". Windows are basically the same size but I can fit more of them on the screen, see more of my layouts at the same time, etc. My monitor array is about 6 feet across, with active windows in the middle, reference material further out, and status at the edges.
So... if you want to edit your schematic while having all those PDFs of the chips up for reference at the same time, buy more pixels :-)