I consider myself an Existentialist. I think it’s a very misunderstood philosophy, much like its precursor, Nietzsche.
Existentialism doesn’t offer neat answers like religion does. It offers some new questions, and some starting points, and some methodologies, but no pat answers.
Camus and Beckett are not the whole of Existentialism, as your reference to the absurd would indicate. We are not “victims”, that’s the first thing to toss out - we are not, in fact, “doomed” to do what we do, we are blessed to be able to decide for ourselves, to shape ourselves as authentic beings, ones that respond to the world as thinking, feeling beings.
We are not bound by a set of rules - where’s the freedom in that? Religion, (or, in fact, any of the old dualistic, moralistic philosophical frameworks,) would have us be automatons, either obedient to our rules or defective and disobedient. Existentialism breaks away from that, says no - man may be a creature of circumstance and Society, but that’s just projection - chiefly, those circumstances that most bother us are created by other people, and so the moral “problem” is the human problem. Once we understand ourselves, truly, authentically, we understand others, a little bit. How, then, can we be “victims”, if we move through the world as actors, not bit-players. Hell, even Shakespeare knew this, better than most modern philosophers.
I’m an existentialist, because it offers real answers, and because it agrees with all my other beliefs - atheism, anti-Cartesianism, functionalism, verificationism, Buddhism, anarchism…