A big feature I recently discovered with Nova, after using it for about the last 3 years, is the backup/restore feature that let's you back up (and restore) your desktop layout and Nova setup. So your icons, icon pack, wallpaper, and other Nova settings (like gestures and folders) all can be restored almost perfectly if you need to do a factory reset or set up a new phone. This, combined with Samsung backup, made a factory reset on my S8 recently a much less painful experience than any previous reset or new phone setup.
The only thing the backup/restore doesn't do is totally replace your widgets. The empty widget box is still on the screen in the same size and location as before, but you basically need to remove it and re-add each widget. And of course you need to log back in to apps which require it (facebook, email, linkedin, etc.).
I'm getting older and tired of goofing around with my phones, so I have not changed much in my phone setup for the past 2-3 years, going back to my Nexus 6p and possibly whatever phone I had before that. Nova makes the transition to a new phone much easier, which is something I don't think most other launchers provide.