I'd rather "write usefully" than "write simply". If a "fancy" word is more useful for getting my thoughts across, then I will use it. I think of "useful" lang

I'd rather "write usefully" than "write simply". If a "fancy" word is more useful for getting my thoughts across, then I will use it. I think of "useful" language as a balance of precision, concision, and understandability. If I use terms that I don't expect my audience to understand, then my language not very "useful" even if it's the most precise and concise. Conversely, there's no reason for me to refrain from terms which I expect my audience to understand if using them makes my language more precise or concise.