The Information has heard from its sources that Apple is working on a 16-inch iPad. It will be launched sometime in Q4, 2023, presumably with an M2, M2 Pro or M2 Ultra chip and "Ultra" branding. https://www.notebookcheck.net/Colossal-16-inch-iPad-reportedly-in-the-pipeline-for-a-Q4-2023-launch.664464.0.html
The price is fine if it has the full power of those chips, but until you can run desktop apps on them even a 12.9" iPad Pro doesn't make any sense.
I use android tablet to see tutorials and books so it is not really a productivity tool for me, but since i also use it to not be seated so much time i found necessary that the sides need to be larger or it needs an handle in each side otherwise i am always putting my hands in screen.
And the iPad will run i(Pad)OS that is designed for phones and is intentionally hindered to not cannibalize MacBook sales 😉 Samsung at least got DeX that works great in mimicking a desktop UI.
Both can't run desktop apps though that have features missing on their mobile versions so either way no option for some but I can see people living with the compromise for the form factor if they don't rely on these features.