This. My partner always speaks frenglish (french english) after talking to her parents. You have to know a little French to understand her sentences. They’re all English words, but the phraseology is all French.
I do the same with Slovenian. The words are all English, but the shape is Slovenian. It adds a lot of soul to your words.
It can also be topic dependent. When I describe memories from home in English, the language sounds more Slovenian. Likewise when I talk about American stuff to my parents, my Slovenian sounds more English.
ChatGPT would lose all that color.
Read Man In The High Castle to see this for yourself. Whole book is English but you can tell the different nationalities of each character because the shape of their English changes. Philip K Dick used this masterfully.