What we do to fit in is go against our true self, instinct and essence. It is a condition of the mind that drives us to not want to be seen as different, exposed or at risk from ridicule or being ostracised. It is all driven by our ego and its fragility.
True vulnerability, as Brene Brown would say, is being able to brave the wilderness and be wholehearted. That takes a huge amount of consciousness and acceptance of what is to be able to truly be and to truly be our soul and pure essence. We have to be prepared to walk the other way to the crowd.
On the surface, it is easier to fit in. However, only in the short-term, as fitting in and going against our true self creates inner suffering and pain.
Once we become conscious and true to ourselves, the pain fades, and we become braver and no longer in fear of the wilderness that being ourselves requires.