Shanghai was a literal backwater of China in all of its thousand year history. Suzhou and Hangzhou were the big city back in history.Funnily enought despite discrimating against the new Shanghainese most of these people aka the Old Shanghainese (Who basically like to act they run the place) don't even actually originate from Shanghai and the "Language/Dialect" basically reflects this. It's basically Suzhounese mixed with Ningbonese with some Cantonese (Cantonese people migrated to Shanghai).
My Shanghainese side of the family are exempt from this because we are one of the very few people who can actualy say they're Shanghai natives.
Shanghai only became prominent during the century of humiliation when it was given as a foreign concession.
So being shanghai native is not a badge of honor or sign of elitism in my view. Shanghai natives r literal farmers and fishermen.