Well, the only new feature I really enjoy in macOS 12 is AirPlay support. I have some movie streaming apps on my iPhone that is not available for Mac nor the Web and I don't have Apple TV or Android TV. So until now I was forced to watch it on the small screen. But now I can easily stream videos from my iPhone to the Mac to watch movies on big screen with all the options available like language and subtitles, captions while I can use my iPhone for other things.
If you are a heavy FaceTime and Apple TV user, I also find it interesting that you can share-stream movies now, watch it together over FaceTime and talk in case that was not an option to come together in person to watch the movie but you want to.
Oh and the new Safari browser with the option to group tabs is also interesting but I heard lot of people complaining about crashes and freezes on Intel Macs, fortunately I am not effected.
Other than that, I don't think you miss anything. There are also improvements to Messages, Pages, Notes but this is the only features I primarily take advantage of.