I hadn't noticed it until now, so possibly my outlook was updated recently on my work-related macbook, while I was gone for a number of weeks: text prediction.
Way too prominent in the text writing box, constantly distracting me from what I actually wanted to type.
Plus, waste of energy to have some language model analyse my text and predict it for me.
How to turn off in #outlook365 for mac:
Edit > Spelling and Grammar > uncheck "Show Text Predictions".
