I'm 33 years old, work in systems engineering. I use my tablet (ipad Pro 9") as an auxiliary device for pleasure and a little bit of work. It does the following, and does them well.
* Spotify player at home. Gets passed around to friends during a get together.
* Fancy annotator - I use the Apple Pencil to draw directly on pictures or even create from images scratch by sketching it out.
* Books - I have several epub purchases that live in Apple Books app. I can read those books on ipad while I'm on the go, or on Mac while at work.
* Netflix watcher while flights - I download some stuff before getting on a plane.
* Youtube by the kitchen - Great for watching cooking related videos while in kitchen.
* Look at photos directly on it, or cast the picture to Mac Mini(my HTPC).
* Notes - I use Apple Notes as my main note taking application on Mac. I rarely find need to handwrite something.. in English or in my native language. Quickly take the ipad out to do just that and continue seamlessly on my Mac.
I think the mileage of use of iPad depends on the user. I for one cannot stand development work, or even writing scripts on the thing. Yes, I have tried/played Pythonista and the bunch of apps in ios.