The one major flaw in all existential philosophy is that it greatly diminishes, if not eliminates, the influences of our past and specifically the insight we gain into the humanities through the reflective thought of past generations. Existentialism replaces the der Wille zur Macht with a hedonistic "feels good right now" mentality. Hedonism sounds bad but who doesn't enjoy some self-debauchery every now and then? I mean it feels good, right? Now, what about agency? How about the idea of determining your own destiny? Self-determination resides in a cocktail of intention, potential, environment, genetics, entropy, and luck. Resting on the empathy centers of the personality schema, agency originates within the illusion of the individual and more specifically the self. The Cartesian trope on doubt, "I think, therefore I am", needs the following firmware update; "We think, therefore we are", with a reflexive hedonistic algorithms to protect lady liberty. Forgetting to mention the significance of doubt is a common misinterpretation. I am not neglecting the empiricist nature of historicity but the pathway to radical empiricism as paved by John Stuart Mill ended in a limited and limiting behaviourism based psychology of the mind. One point for empiricism and one point for rationalism, competing by way of association and interpretation.
Existentialism is kind of like a line drawn in the sand. A reset of thinking. Associated with the psychology of Jean-Paul Sartre and Albert Camus. However temporal it may be, the lessons it teaches us are indelible. To frame Existentialism in this way is overly simplistic and pedantic. Let’s not forget about personal responsibility. This ability to respond is the foundation of volition, as we know it, which pulls Existentialism out of a Hedonistic only philosophy. Is Existentialism still relevant today? Prevalent for sure, relevant? Only through the necessity of pluralism.