You can actually forge a type of “writing mode” in Goodnotes. You can hide the status bar at the top of the screen and move the toolbar to the bottom, so you mostly have the full screen to write. I wrote an article series on Goodnotes earlier this year that goes over this.
I’ve switched between digital and analog journaling too. I landed on a hybrid system where I normally do analog journaling, but there are some situations when digital journaling is just easier.