I'd mainly want it just for laying out certain text centric pages, like letters columns, editorial pages & such. I may need it for print runs, but even that is questionable. I'm surprised how many printers can work from a high resolution print ready pdf file. I work in Clip Studio Paint mainly and was able to export the whole issue in one click last time I did a small print run. Loved it!
iOS has recently gained full support for trackpads & mice as well as keyboards and the new models & accessories are really pushing that, so I could see a text heavy app making the jump in the future.
It does seem pretty powerful for layout stuff, though I suppose it might depend on your needs. For doing things like that it would certainly suffice. @danmaruschak pointed out that there's a free trial going on, which I'd entirely forgotten, over at https://affinity.serif.com/en-us/supporting-the-creative-community/