Bigger objects will stretch it in order to cover whole mesh, while small ones will fit perfectly. Think of texture as square made of rubber. However in most cases it's not necessary to go 4k. You will see improvement with going 2k>4k on 1920x1080 monitor. You can try downsampling the resolution to reduce visible aliasing on lower screen reolution, but it will be too taxing for a laptop. If someone records video in 4k screen resolution, you will need 4k screen to fully apreciate it. That depends on what you are talking about.
