Although Elba had been acting steadily for eight years before the premiere of The Wire, most audiences know him best from his performance as charismatic, sophisticated and ultimately doomed drug dealer Stringer Bell, the nemesis of Baltimore Detective Jimmy McNulty (Dominic West).
Stringer Bell was one of those exceptionally rare roles that give an actor a chance to demonstrate that they can do many things very well. As Stringer, Elba could be intimidating when up against a rival, dryly funny when messing with McNulty, pedantic in his dealings with underlings, seductive in an old-fashioned way that we rarely see on screen anymore, and full of pathos when Stringer's dreams of going legitimate bumped up against the limits of his knowledge, experience and education.
The Wire should have set Elba up to do anything: to be an older Black Panther in a Marvel adaptation; to revitalize the old-school movie romance in an era where Fifty Shades of Grey was bringing more adult sexuality back to the multiplex; to star in a range of historical biopics at a moment when directors such as Ava DuVernay were turning their history to black America's past.
But somehow, the next great role, the one that should have made Elba a genuine movie star, or that should have put him squarely at the centre of his own outstanding television show, never quite arrived. And even when parts did materialise, they didn't quite resonate the way they could have.
After The Wire, Elba took guest roles on series such as The Office and The Big C. As many black actors in Hollywood do, he ended up in a number of sentimental movies aimed largely at African-American audiences, among them the melodramas Daddy's Little Girls and The Gospel. He and Beyoncé co-starred in a stalker drama, Obsessed.
And over and over, Elba was cast as supporting characters in genre blockbusters: as Heimdall, the blind guardian of Asgard’s Rainbow Bridge in Marvel’s Thor movies; as a priest in the second Ghost Rider movie; as Janek in the Alien prequel Prometheus; as a Starfleet captain who lost his sense of mission in Star Trek Beyond; and as the colourfully named Stacker Pentecost, the head of a giant-robot fighting crew in Pacific Rim.
Even as movies like these helped raise the profile of actors like Chris Hemsworth, who plays Thor, and Chris Pine, who anchors the Star Trek franchise, these roles seemed to hem Elba in rather than help him reach the next level.
This is not to say that Elba hasn't done outstanding work in the years since Stringer Bell died at the hands of Omar Little (Michael K. Williams) and Brother Mouzone (Michael Potts) in the third season of The Wire.
He was wonderful as Nelson Mandela in Mandela: Long Walk to Freedom, capturing both Mandela’s militancy and his hard-won patience. But that movie (which also featured a marvellous performance by Naomie Harris as Mandela’s wife, Winnie) came out the same year as Steve McQueen’s 12 Years a Slave.
In an industry that often seems incapable of recognising more than a few black artists at a time, Mandela: Long Walk to Freedom was largely shut out of year-end awards after a modest performance at the box office.
Elba did similarly strong work in Beasts of No Nation, as the Commandant who manipulates and deploys child soldiers. That film, though, was distributed through Netflix, which bets on daring content but doesn't yet seem to have figured out how to make its glut of original movies and television shows capture the cultural conversation.
Arguably some of Elba’s best and most popular work - and the roles that have let him do comedy as well as drama - come in animated films where his face is off-screen, but his rumbly baritone makes an unforgettable impression.
Three of those roles came in 2016 alone, when he played an exasperated water buffalo police chief in Zootopia, Disney's wildly successful allegory about racial profiling and law enforcement; the menacing tiger Shere Khan in the gorgeous live-action remake of The Jungle Book; and Fluke, one of two jocular, slightly bullying sea lions in Finding Dory, a role that reunited him with The Wire co-star West, who also played a blubbery blabbermouth. It's as if Hollywood can only figure out what to do with Elba when it separates his lively, versatile voice from his body.
That's an awful shame, and it speaks more to the entertainment industry's failures of imagination than to anything lacking in Elba’s talent. And while I'm sure this frustrates Elba and his agents, this state of affairs is a loss for everyone.
The space between what Idris Elba is capable of doing and what Hollywood has been willing to give him to do is a measurement of the industry's creative failure and timidity. And for those of us who love to watch Elba work and hate to see him wasted, the weight of performances that could have been but never will be is crushing.