A native speaker told me that "out of employment" is more informal than "unemployed", however, I don't know why and to what extent "out of employment" is informal.
I suspect that it's because "out of employment" is wordy
and contains prepositions
. This logic makes me feel that "take the place of" might be more informal than "replace".
So, is this logic valid? If it is, are phrases like "out of employment" or "take the place of" too informal for academic writing?
Here's the link to my corrected essay where this native ex-examiner gave me the comment.