I have an ipad pro. 90% of the time it's a 3rd monitor for my macbook at my desk. (Very expensive per pixel for that use case!!)
It's nice to have for movies on flights.
A few times a year I use it as a portable second monitor.
I use the stylus for sketching sometimes.
Being self-critical, I overpaid for something I thought I would use more.
I'm not a fan of and don't use the ipad OS features that basically make it more like a mac desktop.