Why do we have personalities? Is it necessary for us humans to have them, or not have them at all.

I know we’re animals, ADVANCED animals, that do compulsive activities like: finding food and eating it for energy, running away or fighting danger to protect ourselves, partnering up with another living organism like our species to reproduce for our population, etc. But our minds are above the basic ways of getting these needs, like all animals do naturally. Do you think that having personalities make our lives less dull or meaningless, that instead of being consuming, opportunistic, reproducing machinces, we feel that we have an individual nature of behavior that makes us feel special and unique from others? What is your theory or opinion on this, I WANT to know.