So of all the people you know, none of them type faster than you, therefore, you must be the fastest typer in the world. ... Okay.
Again, never mind my personal account (or those of other forum members here who have complained of the same issues with the keyboard), just look at the fact that the iPhone keyboard gave birth to that "Damn You iPhone Auto Correction" internet phenomenon. Even if a lot of those are fake nowadays, the fact that it created that phenomenon coupled with the fact that the iOS keyboard has remained largely unchanged should tell anyone that something is wrong.
Could there be any user error? Of course. But to think that it's always a person tapping the wrong key, as Batting1000 is implying, is absurd because missed keys don't happen from tapping the wrong key -- those are called typos. Missed keys happen when the keyboard doesn't register a key press.
For example, if I was trying to type "Hey how's it going?" and it came out as "Hy, how's it oing?" those are missed keys (versus if it came out "hry how's it guing?" -- that would be an example of hitting the wrong keys). This happens all the time on my iPad, and happened frequently when I used to have a 4S.
Not sure why this is so difficult to believe or understand, especially given that it's littered all over the internet, and that others have said they experience the same thing on this very forum (this is but one example from a quick search:
https://forums.macrumors.com/threads/1383529/. I've seen plenty of other threads.).
And when letters are missed, the auto correct thinks you're actually trying to say something else, and it auto corrects it to a ridiculous and unrelated word. Or it just remains a word with missed letters (I often see "thy" instead of "they" for example).
Finally, as I've already said, missed keys is but one of a few reasons why the iOS keyboard pales in comparison to stock Android keyboard (especially more so if you want to compare it to third party keyboards and all their features -- have you tried Android keyboards?).
I'm happy the iOS keyboard works for you and Batting1000, but it is very prone to missing keys, and to think that it doesn't just because you're the fastest typer amongst people you know is irrelevant.