A boomer hit man is given a nightmare final assignment to train his own Gen Z replacement in Simon West’s lifeless action-comedy “Old Guy.”

Christoph Waltz’s Danny Dolinski is the one at an unwelcome crossroads in the film. He’s only partially healed from a hand injury that’s rendered him dependent on pills and unable to aim a gun as well as he used to. Dolinski also seems to be in the throes of a full crisis: We meet him not on the job, or even in flashback to his pre- injury glory, but out clubbing. The next morning, Dolinski emerges in a bathrobe to gaze proudly upon the several younger women who have spent the night.

But a room full of scantily clothed model-types who seem to be there willingly is only a temporary balm for poor Dolinski. While he might still be a viable specimen for the 20-something party girls of London, his game does not hold the same appeal in the workplace. Soon he’ll be getting the dreaded “we’re going younger” talk from his boss, and she’s talking about him, not his love interests. This is a guy who is certain he’s got a lot left to give in the assassin game, and not as a mentor to a “hit man prodigy,” as Cooper Hoffman’s character Wihlborg is described.

Is a familiar conceit like the wise veteran and the cocksure newcomer tired or a classic? Well, it’s all in the execution. And “Old Guy,” stylishly filmed though it may be, is not one of the better attempts, likely hampered by the script from Greg Johnson. Generational clashes should be easy comedic fodder for a screenwriter and two capable actors, but here it lands with a thud. One likes to drink; the other doesn’t like being around alcohol. The more serious ethical questions about hit man etiquette are similarly inelegant. Take this gem from Wihlborg: “Where I come from, one does what one needs to do to survive. That includes killing a kid.”

Hoffman, so perfect leading “Licorice Pizza,” is not served well by this script, which never justifies why he’s such a prodigy at such a young age and doesn’t give him or Waltz any room to play off one another in a natural way. Waltz also can’t seem to choose a lane with Danny, an eccentric hedonist with a soul who doesn’t think it’s necessary to kill kids on the job. He’s also working with his normal accent, which is all well and good, until the movie unnecessarily introduces his Irish mother.

And because action movies of this variety need a woman, Lucy Liu, who deserves better than this (they all do, but mostly her), goes along for the ride. Her character, Anata, is the manager of a Soho karaoke bar that might also be a front for a brothel, but that’s never explored. What is deemed important here is that she’s Dolinski’s longtime confidante, and tags along on their mission to Belfast for — wait for it — a date. It’s a strange subplot in which Anata does go to this date, only to be broken up with. The guy she’s been seeing is not connected to the plot in any way, except as the narrative push to have her fall in Dolinski’s arms.

West is an action and studio system veteran behind “Con Air,” “Lara Croft: Tomb Raider” and various Jason Statham vehicles. There’s lots of shoot-em-up action for anyone looking for that, but there’s not much more to hang on to. “Old Guy” feels of this moment in the fact that it looks good and has a good cast, and yet can’t seem to deliver something entertaining or meaningful. But unlike many of its peers, this was not made by a streamer.

MPA rating: R (for language, violence, some drug use) Running time: 1:33

How to watch: In select theaters and video on demand