My other half has new Ultra, I have an older Ultra model. Stuff i find invaluable that she hasn't used once:

• S Pen
• Modes & Routines
• Secure folder
• DeX (to a lesser degree than the above)

I try to use my phone as a Swiss army knife. Stuff I rely on that most normal users likely dont realise their phone can do:

• Using Kodi the phone becomes fully fledged mobile media player. Great for vacations in case of poor weather (in conjunction with HDMI lead, controller/wireless keyboard)
• OsmAnd navigation has an offline Wikipedia plugin. I set up a shortcut in it so i can display/hide all wiki entries nearby. Brilliant when on vacation
• All my main apps will work offline in case of data outage: navigation, notes, password manager, books, music, podcasts, media etc etc
• Password manager has more uses than simply handling passwords
• Playing video sites in the background ...with a timer if desired
• Browser with uBlock "etc"
• Manipulation of .pdf files
• A good launcher. Mine is always set up the same regardless of device - I can access any app within 2 swipes & 2 taps
• A good car dock
• Most don't realise that a simple DNS entry can help reduce the amount of ads they see
• All manner of nerdy tech shit to interact with stuff on my network. No normal human needs to know that this usage factor exists

And most importantly ...using the camera in landscape so images/video can be viewed properly on a TV or monitor. And not using digital zoom in the dark to record an entire concert from row Q