Shemot 1:5

וַֽיְהִ֗י כׇּל־נֶ֛פֶשׁ יֹצְאֵ֥י יֶֽרֶךְ־יַעֲקֹ֖ב שִׁבְעִ֣ים נָ֑פֶשׁ וְיוֹסֵ֖ף הָיָ֥ה בְמִצְרָֽיִם The total number of persons that were of Jacob’s issue came to seventy, Joseph being already in Egypt.

This is there to inform us of josephs righteousness. It shows how joseph was righteous from his fathers modest house to when he became king of egypt. The change of position did not affect his character