Samsung tablets themselves, and other andriod apps, support handwriting to text with the S-Pen. Goodnotes for iOS already supports the feature, so the functionality/coding for this already exists in the app. A large reason people use Goodnotes is to make notes easier to read and study. Currently, the inability to do this, despite the coding already existing in an app version and it existing on other apps, is crazy.

If you offer it for iOS, and other andriod apps support it, there isn't a reason to continue to neglect to add it to the iOS app.