No device should come without a simple PDF editor to add and edit text, add, remove and sort pages.
But Apple loves that sweet cut of the subscription-based apps that offers absolutely nothing after the first download and that should clearly be one-time-payment $5 apps instead. Or freeware, if Apple didn't build the store to make it impossible not to lose money with freeware.
I hate how hard it is to even understand if a "free" app with IAP will do anything useful before I pay.