People who depend on LLMs to polish their words will run into the same problem as people who rely on autocomplete functionality: their language skills will suffer.

There's nothing wrong with using tools to check written text, but I'm wary of blindly accepting any suggested fixes. If I see a red underline I'll consider whether the word is actually fine first (English is not a static language, and spelling dictionaries are not complete), and if it looks wrong I'll try fixing it myself before reaching for the suggested fix.