Martin Scorsese’s 3-1/2 hour mobster drama “The Irishman” stands at a crossroads in American movies, when we are reconsidering how we watch movies and arguing about what is cinema instead of mere entertainment.

“The Irishman,” which in many ways is a culmination of the 77-year-old director’s astonishing career, provides plenty of ammunition in both of those discussions.

In the run-up to “The Irishman’s” release, Scorsese ignited a debate when he said he didn’t consider the Marvel franchise “cinema,” because those superhero movies take no risks. He was called an elitist by some, but praised by fans who think Scorsese — the maker of “Taxi Driver,” “Raging Bull,” “GoodFellas” and “The Departed,” among others — has the authority to pass such judgments.

Some even suggest “The Irishman” itself isn’t cinema, because it was bankrolled by the streaming service Netflix — which will debut the movie on Wednesday, Nov. 27, where far more people are likely to see it than will in theaters.

Is “The Irishman” cinema? That’s for film scholars to judge decades from now. I will say that “The Irishman” will likely be the greatest American movie of 2019, once the dust settles — and, because of the Netflix connection and how Scorsese anticipates that, the most groundbreaking movie of the year.

The title character is Frank Sheeran (played by Robert De Niro), who as an old man tells stories of his days in the mob. “I hear you paint houses,” more than one person says to Frank, employing a slang term for a hitman — and we see several flashbacks to Frank painting a wall with the blood of one of his victims.

Scorsese and screenwriter Steven Zaillian (“Schindler’s List”), adapting a book by Charles Brandt, begin in the early 1950s, when a young Sheeran, who’s not above some pilfering of his truck loads, draws the kindly attention of Russell Bufalino (Joe Pesci), one of the top figures in the Philly mob. Bufalino sees potential in Sheeran, and starts finding jobs for him.

Note that Scorsese didn’t hire younger actors to play De Niro’s and Pesci’s characters as young men. Instead, he uses the special effects magic of “de-aging” the actors — ironically, a technology that has evolved in the Marvel movies, with such actors as Samuel L. Jackson and Michael Douglas. The “de-aging” limits the emotional range for De Niro and Pesci (who are each 76), but since they’re playing mobsters who seldom betray their feelings, that problem is negligible.

At one point, Bufalino gives Sheeran a special assignment to help out “our friend in Detroit.” That friend is Jimmy Hoffa, president of the Teamsters union and one of the most famous men in America from the ′50s up to his still-unsolved disappearance in 1975. Hoffa is played by Al Pacino, and the actor’s loud acting style is a hand-in-glove match for the blustering, larger-than-life labor leader.

Sheeran’s devotion to his job, and his habits of intimidation and violence, take their toll on his home life. We see this most starkly with his daughter Peggy — played as a little girl by Lucy Gallina, and was a wary adult by Anna Paquin — who is shocked by her father’s violence and shrinks from the attentions of “Uncle Russell,” but forms a bond with the people-pleasing Hoffa. Paquin has only a few lines of dialogue in the film, but her watchful eyes become the movie’s emotionally bruised conscience.

Scorsese and his team — specifically cinematographer Rodrigo Prieto (“Brokeback Mountain”) and Scorsese’s longtime editor, Thelma Schoonmaker — present Sheeran’s reminiscences with a chilling equanimity. In Sheeran’s mind, these are all things that happened in his life, and there’s no more introspection to a killing than to how his favorite hot dogs are made. The moral judgments come from outside forces, including his daughter and the audience.

Scorsese has managed to create an intimate epic. The scope of the story is huge, spanning decades of American history through Sheeran’s passive view. But the emotions are tightly held, largely conveyed in close-ups that work on a theater screen or streamed at home — proof of how Scorsese looks several moves ahead as he makes moves. (The 3-1/2 hour running time also hits the sweet spot between a theater sitting and home binge-watching.)

“The Irishman” isn’t likely to be Scorsese’s last movie as director (he’s announced a Theodore Roosevelt biopic with Leonardo DiCaprio), but it could serve as a summation of his career. There’s the heartbreakingly good performance from De Niro, continuing the one of the greatest actor-director pairings ever. There’s the director’s reunion with Pesci, Harvey Keitel (as a Philly mob boss) and “GoodFellas’” Welker White (as Jimmy Hoffa’s wife, Jo) — along with strong supporting work from such new players as Paquin, Ray Romano, Bobby Cannavale, Stephen Graham, Jesse Plemons and Jack Huston.

What’s most striking is the elegiac tone, as “The Irishman” is all about death. With nearly every new character, Scorsese gives us a bit of onscreen text describing how each died — sometimes from terminal illnesses in old age, but more often by violence. Sheeran, in his nursing home, is surrounded by death literally and in his soul, and his story is the last thing he has to hold onto, the last job he has to complete, before the end that awaits us all. It’s that story that Scorsese has been working toward for more than 50 years.

★★★★
‘The Irishman’
Director Martin Scorsese brilliantly crafts an intimate epic about death, violent and otherwise, through the eyes of a mob hitman who befriended the labor leader Jimmy Hoffa.
Where • Broadway Centre Cinemas (Salt Lake City), Megaplex Jordan Commons (Sandy)
When • Opens Friday, Nov. 22. (Also debuts, Wednesday, Nov. 27, on Netflix.)
Rated • R for pervasive language and strong violence.
Running time • 209 minutes