I had my M1 Mac mini out the of box and acting as a headless Roon Server in less than 30 minutes. I have updated the macOS several times now, using Screen Sharing, and have never had to hook up a monitor or keyboard after the initial setup. I am not using any video port dongles to fool the Mac mini into thinking a display is attached.
Of course, I have been using Macintosh computers since 1983…yes, before they came out officially on 1/24/84.