I've never had an AI write for me. I don't really understand why people would do that unless English was a foreign language, perhaps--even then, it should be translating, not writing.
It's not that hard to learn your own language. You presumably are using it constantly, every day. It should be a high priority to know how to spell the words you're using, IMO.
I do make occasional mistakes, but mostly from using the "swipe" keyboard on my phone, and failing to catch the mistake.
I don't proofread things like text messages or forum posts--only important emails, or documents that will be posted publicly at my business, and therefore reflect on me.
If I'm not sure about a word I'm using, I either look it up, or rephrase to use words I'm more familiar with.