Like all predictions about future technology, Star Trek was both right and way off.
Padds are almost used like portable storage devices. Want to give someone a book? Load it onto a padd for them.
But who wants to deal with searching through the UI for pertinent info when you can have several PADDs each attuned to a specific set of data?
They can even have their own special UI! The way they talk about reconfiguring panels makes it seem like you can build your own UI on the fly, especially the time Worf yelled at a dude who put the con controls in the engine room of the defiant and didn’t use the standard layout.
I’m more amused by Jake writing his stories on a PADD with a stylus, but you see it and it’s all printed text.
Production reason: without a stylus it looks like he’s reading, not writing. Without one, dialogue like “I’m writing a book” would come across as lying, which can completely change a scene for the worse.
In-universe lore reason: Jake is a romantic and probably feels that the more tactile approach is better for his creative process.