Hollywood is all about mythmaking, and there's nothing the institution of the movies or audience love as much as an underdog made good story.

Sly, the hagiographic documentary about the life of Sylvester Stallone, leant the furthest into doing so I've seen in an onscreen celebrity memoir in recent years, combining Stallone's determination to be a writer and actor and trying to make them seem like Herculean feats of physical strength and determination.

Structurally and creatively, the filmmakers behind these kinds of projects want them to be entertaining, so they have to...not exactly invent overcoming-the-odds stories, but certainly draw metaphors with extreme, dedicated and lifelong effort to overcome hardship.

But sometimes, there's just no real backstory there, and as beloved as Gene Wilder was, the story this movie tells of his life just isn't that interesting.

It depicts a reason for him wanting to be funny (his mother was always in ill-health and an insensitive doctor took him aside and told him never to antagonise or upset her), but his entry into the world of the theatre is barely mentioned, his longtime collaborator and friend Mel Brooks spots him in a play and casts him in The Producers, and the rest is history.

One negative review I read complained because it never gets into the 'complex tragedy' of Wilder's life, but I suspect there simply never was one – certainly nothing more tragic than we all go through just to live.

He was in a bunch of movies, many of which touched millions (the biggest surprise of the whole film was that Willy Wonka and the Chocolate Factory wasn't a financial success), was married a few times, got old and died of dementia.

He wanted to direct and made a bunch of movies himself, many of which didn't work and you won't even remember exist, he liked painting and did that, he liked writing and did that, publishing a kids' book and his mid 2000s autobiography Kiss Me Like a Stranger. There was no titanic struggle for love, acceptance or recognition.

Maybe I wanted more from what drove him (a need to be taken seriously like Stallone, the constant search for acceptance from his father like Steve Martin) and it just wasn't there. However charming Wilder and his work was I found the whole thing slight.

There are plenty of talking heads like Brooks himself, Wilder's widow, Richard Pryor's daughter, who saw their relationship in action and Peter Ostrum, who played Charlie opposite Wilder and never acted again, all talking about how wonderful and warm hearted he was.

The high point – and something the makers of the movie were incredibly lucky exists – was that Wilder narrated the audiobook version of his memoir, so he gets to give context to his own story.

He evidently wasn't the type to indulge in obsessive self reflection or document everything about his life on video like other celebrities or stars (See Val Kilmer in Val), so without the words of his own book there'd be very little of him still around except for the movies – certainly not enough to make a documentary about his life.

It won't challenge you, it's more like a combined party/wake, everyone reminding you and themselves about everything we loved about him. That's fine enough I suppose, but it probably says something about how these celebrity documentaries prime us to expect mythologies of suffering and triumph worthy of the ancient Greeks, when they're really about people who are just luckier than millions of others.