The main benefit I've found with Gboard is a larger vocabulary, and perhaps a less aggressive autocorrect that doesn't constantly try to correct technical terms into similar common words.
Not sure if Google just gave up on updating the iOS variant or if Apple holds it back intentionally (probably a bit of both) but they pale in comparison to their Android counterparts.
I’d prefer a useable stock keyboard but I take your point.
Anyway, my point regarding the UX still stands. Apple's UX is barely as good as other major player's - not great, not terrible. Mediocrity isn't what Apple should be aiming at.
I do the same, and I find it way better.