For at least 10+ years the specs for DisplayPort output have been higher than for HDMI. DP has supported higher HZ (refresh rate) higher resolutions. Dell has been in the forefront of pushing DP over HDMI in its business desktops (OptiPlex) and business laptops (Latitude). You can easily see this at Ebay by looking at 2x (even 3x) DP outs in most OptiPlex starting years ago. (the lowest grade OptiPlex usually have a DP and an HDMI out)
4K HDMI has resolution, refresh rate, and performance that is more than good enough for my aging eyes.