"Fight Club opened my eyes. Now I always beat myself up because nothing matters. We need to destroy all forms of capitalism. We need to suffer because we are worth nothing. We need to start smoking, and look cool like Tyler Durden" (Obvious exaggeration)
But that's sometimes the feeling I get from some Fight Club fans. But I think that that's dangerous and by far not the right approach of interpreting Fight Club (at least in my eyes)
Tyler has a lot of clever points, "The things that you own, end up owning you" or "We are a generation raised by women".
The dependence on things, materialism and capitalism, the grey look of an office, the loop of never escaping a life routine you hate as well as the de-masculinization of modern society, are all interesting, and in some way true.
But this serves the purpose for Tyler, the antagonist, being the exact opposite of the narrator, our protagonist.
Our protagonist is flawed, he is unhappy, and he blames everything (sometimes reasonably, sometimes non reasonably) on everything around him. That's why he creates a fantasy, an alter ego, Nietzsche would say an "Übermensch". He creates an ideal of himself. But because he is flawed, his thinking is toxic, Tyler Durden, the best version of him, the man he is aspiring to be, is also flawed (obviously shown when he turns into full terrorist and fascist leader).
When Tyler Durden, is the ideal of you, then being Tyler Durden, does not mean smoking and destroying yourself (unless you in real life are just like Nortons narrator in the film), but to be what you truly want to be. Imagine a perfect version of yourself, and that's your personal Tyler Durden.
I think that's the main message of the movie.
Half of it is criticizing materialism, and how it can affect people in our society (leading to terrorism and fascism)
and the other half (your idolizing view on Tyler Durden) is telling you to embrace what you want to be, your charismatic, capable, and personal Tyler Durden.