1. Safari Profiles. I used this browser as my primary browser for a long time, but had to use another browser (Chrome) for work, to be able to separate sessions, etc. Since DB1 I use only Safari. And it works great.
2. Widgets. I have two monitors, and love that in one of them I can see widgets with some useful information. Just wish more apps were ready with widgets.
And a quick self-promotion. I am developer of the application OpenIn, and for macOS Sonoma I have added support for Safari Profiles https://loshadki.app/blog/2023-08-23-openin-4-1-beta/, this is the only (as far as I know) app that will let you redirect links to a specific Safari Profile based on various configurations you make.