That monitor has a noticeable lower pixel count.
replyDell U4025QW: 5120 x 2160 = 11,059,200 vs Apple Studio Display XDR: 5120 x 2880 = 14,745,600
So your display has 25% less pixels.
It’s quite possible this is running with a reduced color space (chroma subsampling). Degradation happens automatically based on available throughput and most people don’t notice.
replyFor desktop use? Chroma subsampling is obvious. DSC compression, on the other hand, is not. DisplayPort and HDMI support both.
replyIt’s obvious if you use a test pattern and/or know what to look for: https://testufo.com/chroma
replyI had no idea what it was for the longest time. As it turns out, macOS frequently enables it even when it’s unnecessary, and without any way to override.