Authenticity means to be real, to be yourself and not someone else. No one can be you, better than you and vice versa. It's unfortunate that the world is filled with people who aren't themselves, they've deviated from their true selves trying to be someone else. These often are in quest for perfection and societal acceptance, people believe being like someone else the society accepts would give them a better chance to succeed- which often only leads to unhappiness at the end. Fans oftentimes want to be like their model or celebrity, they change the way they dress, change the way they talk, change how they walk, change their lifestyle in order to fit that of the celebrity- and most times they do this with a lot of cost attached.
It's often difficult to be someone else, it takes a lot of compromises and restlessness to appear as whom we admire. We pretend to be who we are not and it takes more hard work to keep acting as whom the world believes we are. Be you and you'll do better at whatever you are. The fish can live seamlessly in water without struggles but the day it chooses to take up the place of a frog on the outside, would be its end. We equally die to ourselves, living as another.
There's a need for us to be authentic. First, because there's no extra work being yourself. It's easier to be ourselves than living the life of another. Secondly, we are lost each time we tend to be like someone else, lost to self and we lose touch with the true us. It's important to understand that we are humans, and that makes us imperfect in one area. Even the models and celebrities we desire to be like are imperfect in a way. Being authentic not only helps us appreciate ourselves but also helps us find peace in who we are.