Age becomes Marc Maron — maybe. The comedian, actor, and podcaster is the subject of Steven Feinartz’s documentary, “Are We Good?” It begins with Mr. Maron waiting to go onstage at Los Angeles’s Comedy Store. When he’s not pacing, Mr. Maron sits with his arms folded, nervously jiggling his leg. He gripes, albeit with admiration, about the cadence and craft of the unidentified comic preceding him.

Mr. Maron is less kind to Mr. Feinartz. “You’re going to destroy me with this stupid movie,” he tells the camera. The charm offensive continues: Mr. Maron calls the director annoying and then predicts that not only will Mr. Feinartz come to hate his subject, but he will subsequently post calumnies about the comedian on social media. At which point the curtain opens and Mr. Maron walks onto the stage to a welcoming round of applause.

We hear from a handful of Mr. Maron’s comrades in comedy. David Cross testifies that few people have been able to tolerate him. W. Kamau Bell describes Mr. Maron as “his own worst enemy.” Nate Bargatze, playing the diplomat, avers how Mr. Maron is underrated, but, really, he’s not the type to play arenas. Later, we watch as Mr. Maron talks smack about Dave Chappelle and Joe Rogan. Mr. Feinartz is invariably there to take down a peg or two. That’s what he gets for having the audacity to think that Mr. Maron and his travels are worthy of examination.

Mr. Maron isn’t the first subject of a documentary to complain about the proceedings at hand. Throughout Terry Zwigoff’s “Crumb” (1994), the cartoonist Robert Crumb bristles under the camera’s gaze, as did the comedian Gilbert Gottfried in Neil Berkeley’s “Gilbert” (2017). Given Mr. Maron’s prickly reputation, Mr. Feinartz knew what he was getting into; so did Mr. Maron. The jibes the former has to withstand from the latter are less irascible than self-serving. “Performative” is a term in desperate need of retirement, but Mr. Maron’s grousing has little heft.

Then again, there’s no one Mr. Maron bedevils more than himself. “Are We Good?” traces a bumpy, often drug-addled life that ends up in a good place. After spending close to 25 years trying to make a go of it as a stand-up comedian, a broke and twice-divorced Mr. Maron started a podcast titled “WTF.” Setting up a studio inside of his garage, Mr. Maron began interviewing a litany of cultural figures and proved a deft, if sometimes contentious, hand as a conversationalist. Word got around; popularity ensued. The long-suffering insufferable comedian had found his niche.

Actors, directors, authors, musicians, and even a president — that would be Barack Obama — hunkered down inside Mr. Maron’s garage. The most significant guest was likely director Lynn Shelton. Say what you like about hindsight, but the initial conversation that took place between Mr. Maron and Ms. Shelton is suffused with, and there’s no other word for it, wonder. A spark was lit — though it took time, as well as the relinquishing of contemporaneous relationships — for a romance to gain in intensity. Is love capable of lessening the cynicism of a cranky comic? You might as well ask if Shecky Greene was temperamental.

The relationship was short-lived. Shelton died of a rare blood disease in 2020, a story that is elaborated upon in heartbreaking detail throughout Mr. Feinartz’s picture. Mr. Maron has spoken of his grief, both on “WTF” and in his stand-up routine, and has come through it a transformed man. Actually, make that relatively transformed: Mr. Maron is still abrasive — really, he can’t help himself — but his bitterness has diminished and his gratitude is less begrudging. Count “Are We Good?” as one small step for humankind.