[oneplane]

Depends on how you run it. A screen is more than just "4k", or 4000 pixels wide. The amount of pixels in total spread out over the physical dimension, depending on the aspect ratio and the distance between you and the screen as well as the rendered density by the computer together make the result.

So, you could use a 27 inch 4k display at 16:9 aspect ratio (which is 3840 by 2160 pixels) in a way that gets you the native resolution which results in much more usable space but the displayed quality isn't all that great. You can run them at 2560x1440 rendering which sacrifices some pace for much improved quality. Works well when you don't sit super close to your screen. Or, if you like more space but still have a little better quality than the jagged mess that is the native resolution, you could run it at 3008x1692. Close to fully usable space but still way better in terms of quality.

The scale of your computer rendered interface and text versus the actual pixel size and density on your display gives you a balance to choose from for space vs. quality. Which one works best is a combination between physical distance to the screen and personal preference (which mostly forms based on cognitive load).