Personality exists because it is useful. Evolutionism understands personality as an adaptation, developed by our brain through millennia.
All social animals have personality. Whoever has had a cat, or a dog, knows this is true.
Personality is not something “false” that we need to discard, to ditch or to demonize. It is there because it enables us to navigate our social life.
It is true that there are layers to it, and some aspects that we try to hide, even from ourselves. But this does not mean that the aspects we show are false. Personality lies deeper. It lies in our deeper emotions and motivations. It lies in the reason why we choose to show or hide in the first place.