when should you think about using a NoSQL database for user profiles

hey everyone im trying to nail down some best practices for storing user profile data weve been using a relational db but as we scale and add more complex profile fields like custom attributes social connections etc im wondering if a nosql approach might be better specifically im thinking about document databases or key value stores has anyone made this switch or have strong opinions on when nosql really shines for this use case versus sticking with sql what are the trade offs youve seen