The rags-to-riches story of Ralph Lauren is something to behold. Born Ralph Lifshitz on 14 October 1939 in the Bronx to Ashkenazi Jewish parents from Belarus, he shared a bedroom with his two brothers and had no formal fashion training. Instead of going to a prestigious fashion school, he started his career flogging ties from a drawer in a showroom in the Empire State Building. Now, that is but a distant memory; Lauren’s brand is worth $6.3bn and recently celebrated its 50th anniversary. With a style that is a fever dream of WASP-ish Americana – timeless and conservative – the Ralph Lauren story feels like perfect fodder for a documentary like HBO’s Very Ralph, which aired in the US earlier this week and in the UK on Friday.

Director Susan Lacy tells the fairytale breathlessly, while also showing that Lauren was at the forefront of many of today’s fashion concerns, from athleisure to increasing diversity in his ad campaigns (he made waves when he featured Tyson Beckford, an African American model, as the face of his suits). And yet, despite all this potential, the film falls flat. Instead of narrative tension we are fed endless scenes of his charmed life: here’s Ralph throwing the first pitch at a Yankees baseball game, or emotionally embracing Oprah, or dressing up like the Marlboro Man in a dusty cowboy hat and tight blue jeans to stand round the fire at his Montauk ranch. Lacy only hints at the hollowness behind Lauren’s Jay Gatsby-esque persona. “It’s performance art in which you participate. It’s a stage set in which the clothes are on sale,” says fashion writer Judith Thurman, talking about Ralph Lauren shops, though she could be dissecting the man himself.

Facebook Twitter Pinterest Model behaviour ... Lauren with Kristin Darnell. Photograph: Home Box Office (HBO)

That the documentary chooses to omit Lauren’s cancer scare – he had a benign brain tumour removed in the 80s – also speaks volumes. Very Ralph has taken amazing access to Lauren’s inner circle and pumped out nothing more than a series of approved images of the man, all–American snapshots that would not be out of place in a Ralph Lauren moodboard. It is the documentary equivalent of walking through the after-spray of a luxury perfume, a souped up version of Through the Keyhole. Which is a shame, partly because we are living in a golden age of fashion documentaries (starting with The September Issue through to The Gospel According to Andre, McQueen and Halston) that show you can mix the fabulous fantasy of the catwalk with the darker realities of the fashion industry.

But its issues run deeper than that. In the film, the late Karl Lagerfeld describes Lauren as: “the American designer who best represents America and American style for the rest of the world.” But what version of American style? And what America? Post–Trump, the truth is that a very white, very male take on the American Dream is hard to stomach. This is touched upon all too briefly at the end of the film. “[Lauren’s] adherence to these narratives of America that are core to his brand can get a little stale,” says New York Times fashion critic Vanessa Friedman. “Particularly at a time when a lot of people who have not felt included in these narratives are finding a voice and are demanding that we rewrite how we think about all these stories.” And there lies the problem: in its faithful reading of Ralph Lauren, the film renders the classic American Dream, in its purest form, as something that is still attainable, something to strive for, when for many it is forever soured.

Very Ralph airs on Friday, 9pm, Sky Atlantic in the UK, and on HBO Go and HBO Now in the US