It is possible - see https://www.techjunkie.com/turn-off-autocorrect-iphone/ for instance.Yeah I always think apple can go ———-itself when their technology thinks it knows what I am trying to say better than I actually do. How do you turn it off??
However, for me the issue is not to turn auto-correct off, which would be catastrophic for me for a variety of reasons, but that the algorithm has an utter lack of context awareness. Even simple cases like "well" versus "we'll" are not handled in a context-dependent way. The algorithm simply checks word-by-word, which is hopeless and hasn't changed fundamentally since the 1980's. Even looking at word transition probabilities between pairs of words, let alone having some semantic understanding of the sentence being written, would be a huge step forward.