Do we have freedom of identity or not?
Do you get to choose yourself or do you get assigned a self? Gender is assigned, races are assigned, people didn't choose it. Is the gender you choose more legitimate than the gender assigned to you? Is the identity you choose more legitimate and authentic than the identity assigned to you? When people say "be yourself" very few people are willing to accept another person as they internally see themselves. So what does "be yourself" actually mean?
Identities are currently forced on people by threat of violence
True freedom of identity means the ability to discover and create yourself without being assigned a de-facto identity. Gender and race are both assigned at birth. Nationality is also assigned at birth. Rich, poor, also may be assigned at birth. Should a person automatically accept and internalize the identity given to them by their parents, the media, the government, the church, the local bully, or should they never internalize an identity which they didn't create for themselves and or embrace willingly?
If people wont accept your true identity then they don't want to know the real you
As unfortunate this as is to say, a lot of people seek acceptance for who they are. Their chosen identities often are rejected by everyone, their parents, their friends, the town, the government. If we look at the census it will ask "what is your race", and request that people choose a box to fit their identity into. It will ask for a gender, which is another box which people must accept being oen or the other. So typically a person has to check off "white" or "black" or "male" or "female" whether or not this is how they see themselves internally, merely because this is how others externally identify them. As a result we have identity politics which appeal to these often internalized assigned identities, and this may limit the growth of the individual.
Conclusion
Freedom of identity promotes individualism. Assigned identities simply make it easier for humans to remove individualism and collectivize large groups of people who may have nothing in common except superficial traits. Actual identity is more about how a person thinks and sees the world than superficial traits and so a chosen identity is more accurate for knowing the internal identity which is the most accurate form. Deindividualization encourages individuals to ignore their true self and seek to adhere to popular stereotypes of how they are supposed to act. Examples: "Be a man", "Stop acting white", "Stop acting black", "Be a real American", when in reality these are just what other people want you to be for their own purposes. To truly be yourself you have to know yourself as an individual, as a "snowflake".