It is almost certain to be a hardware issue. The only real options are to self repair (tricky if you aren't adept at that sort of thing), buy a new iPad, or just put up with it.
As a work around for the typing problem you can probably use the keyboard in split or floating mode. That will allow you to avoid the dead parts of the screen.
On supported models, type with a split keyboard, or undock the keyboard and move it to the middle of the screen.
support.apple.com
Note: I don't seem to have the split keyboard option on my iPad Pro. The floating keyboard does work, though it's not nearly as handy for lots of typing.
Note 2: The 12.9" iPad pro isn't on the supported list for split keyboard. Most smaller models are. Works fine on my iPad Mini.