If you regularly switch languages or, even worse, use multiple languages in the same messages, autocorrect gets in the way more than it helps. In monolingual contexts it’s almost always set to the wrong language (based on the one used previously) and what comes out is just a jumble. In multilingual contexts you just spend as much time on switching the keyboard language as on the actual typing.
Also, I’m not sure how it is today, but 5-8 years ago I knew more words in my native language than iOS autocorrect and got tired of it “fixing” them.
They have the feature, sure, whether it works properly for the languages you are using is another thing altogether.
Somewhat close languages (french/english) are often not great, and adding CJK with anything other than english to the mix is also a recipe for a bad experience.
Even for just English, it gets some words wrong constantly for me. I would love to be able to watch someone type in their phone to see if I'm just using it wrong
Well, maybe it’s just personal preference, but I use Dutch and English (a closer language pair than FR/EN) on Android and iPadOS, and it works great for me.
Of course, you still need to switch for CJK languages (because they need an IME), but that’s a given.
Also, I’m not sure how it is today, but 5-8 years ago I knew more words in my native language than iOS autocorrect and got tired of it “fixing” them.