Central Theme
The show's most pronounced recurring theme is authenticity. The five leads - Barry, Sally, Gene, Fuches, and Hank - all fail because they insist on lying to each other, and even more so to themselves, about what they want, who they are, or what they're afraid of. Barry deludes himself that he can be a good person without any real fundamental change on his part, Sally deludes herself that a Hollywood acting or writing career will give her enough validation, Gene deludes himself that he's a minor legend when his colleagues view him as a has-been (or a never-was in some cases) and he impulsively chases after fame without considering the consequences, Fuches deludes himself that he's helping people like Barry "fulfill their potential" rather than sending them down self-destructive paths, and Hank deludes himself that he's destined to become a great crime lord when he knows he would be happier in legitimate business. Ultimately, all of them are very unfulfilled, and only succeed or find peace when they move away from those delusions. For a series brimming with Gray-and-Grey Morality at best and Black-and-Gray Morality at worst, there is one consistency: those who deny who they really are pay a hard price, and those who can face their real, authentic selves are shown mercy.
In the series finale, Fuches is arguably the only person who achieves total happiness: once he accepts that he's a bad person and stops trying to pretend otherwise, it gives him the motivation to do right by Barry for once—namely, by defending Barry's innocent son John in the final shootout with the Chechens—before he safely disappears into the night. Sally, meanwhile, is a close second: she doesn't completely outgrow her need for validation and is still cold and distant towards the now-teenage John, but being a high school theater teacher has given her greater peace than continuing to try to succeed in Hollywood ever would. And even Barry gets a posthumous reward for an attempt to be authentic with himself, and with the world, by finally deciding to turn himself in right before Gene almost immediately shoots him dead: he is redeemed in the public conscious and remembered by history, however erroneously, as a tragic military hero with his name forever synonymized with a reverent, if hacky, biopic. Lastly, Hank and Gene respectively pay the price for failing to accept their real natures as, respectively, a businessman and a faded has-been, and the former dies by Fuches' bullet for refusing to accept responsibility for Cristobal's death, while the latter, having been blamed for Janice Moss's death but no less determined to win back his fame, is sentenced to life in prison for killing Barry and throwing away his only chance at exoneration.