One big advantage of GoodNotes is that it has both iPhone and macOS versions of the app.
I use the iPhone version for quick access of notes on the run. I’ve found myself refernecing notes for a side discussion with colleagues I bump into in places like elevators, water cooler etc.
The desktop version I use mainly for managing my notes, deleting old notes, etc.
This to me was the selling point for GoodNotes.
I’m glad you’re happy with GoodNotes. But FYI, Notability has iOS (phone and ipad) and Mac apps as well.
I use ZoomNotes when I need a lot of flexibility with adding graphics, dragging in images or snippets from other apps, Copied or Gladys. ZoomNotes has more features than any similar app on iOS. It takes a while to get used to the controls and menus (very idiosyncratic). The page can be a standard size and orientation (A4, US Letter, Portrait, Landscape) or it can be an infinite canvas. Pages can contain subpages for drilling down into a topic. Elements on the page can be hyperlinked to other elements in the page or document – and I can create slideshows or animate the page.
Beside drag and drop, there are lots of import and export options (more than Notability or GoodNotes). And the app can sync via iCloud with its desktop companion, ZoomNotesX. It is not the prettiest app, but is the most powerful. It does not have text recognition or handwriting conversion.
I use notability when I attend a course as its simply the best IMHO for mini diagrams, scribbles and text. I have it on the iPhone and iPad and even although I purchased it many moons ago, it still gets updated to this day.