That feels like an argument that could apply to bar any category of apps to compete with Apple ones on the phone.

For instance giving a special placement to Apple Music and not allowing other apps to get the same privileges, because music playback needs to be efficient, and a bad music experience would hurt the iPhone's image. Same for movies, same for ebooks, same for spreadsheets (including needing to execute macros, so security risk is through the roof)

I feel I could get paid by Apple to come up with excuses for each app they need any.