Several things. Communications...including texting...video meetings, Photographs on the go for posting to MLS, Video presentation walkthroughs, PDF's on the fly, creating...filling, and signing documents and contracts, scanning documents, jotting down notes with the Apple pencil(no separate pad of paper required), etc...
No more need for a still or video camera, no more need for a scanner, no more need for pad of paper...
All this and more are just more intuitive and quicker with the iPad. Has cut my workflow and amount of devices dramatically.
Edit: You'd also be surprised at how far the Files app on the iPad has come. I do a lot of my file management with that now, along with
FileBrowser Pro. Talking to my Mac Mini, external storage, and PC's is really easy with either app.