I often see a sound engineer with an iPad on music gigs. The form factor allows you to walk around the room and adjust the sound easily to tame resonances and such.
It’s not so good for typing text or programming, but where it makes sense to have a portable slab of screen that works reliably there is probably an app that does it.
An artist who draws might consider iPads to be serious drawing devices.
I agree that early third-party styli were a pain - I used various Jot versions, which were better than nothing but not great.
But the Apple pencil + Procreate is actually great, and a fulfillment of the iPad's original promise in the drawing space.
The core issue is the hobbling of promising hardware because it doesn't fit the platform owner's vision.