The problem is that analog YpbPr is not the optimal signal for a PC monitor. Even if it looks ok, USB C RGB signal (Displayport) will look better.
I don’t know why Mac Mini M1 (and other apple computers) read some monitors as TV’s, and send YpbPr to the monitor, especially for Dell it seems to default to this despite Dell support RGB 4:4:4 as well, explained in below link.
https://spin.atomicobject.com/2018/08/24/macbook-pro-external-monitor-display-problem/
From Dell monitor manual:
Input Color Format. Allows you to set the video input mode to:
• RGB: Select this option
if your monitor is connected to a computer (or media player) using the USB Type-C, DisplayPort, or HDMI cable.
• YPbPr: Select this option if your media player supports only YPbPr output.
Consensus seems to be that RGB is the best signal for a computer monitor, I don’t know how much better it would be vs YpbPr on my Dell U2720Q since I can’t get RGB to work. But I would like to know and would like to have the option to try. It should be a simple fix for Apple to have a switch in display settings to select either RGB or YpbPr output, same as Nvidia and AMD. This issue has been going on for more than 10 years with Mac computers and external monitors, users have made scripts (which no longer work for M1) to fix this problem. Should not have to be like that.
Here is another discussion:
https://forums.macrumors.com/thread...play-fuzzy-fonts-colors-ypbpr-vs-rgb.2276345/