Robert Downey Jr is killing blockbusters - or is it the other way around?

The actor pocketed $15m (£11m) for less than 15 minutes of screen time in latest Marvel film

Why do we care about how much actors get paid? It's a question that rears its head every time a new salary list is released hammering home what we already know: film stars get paid too much. It's not a sensational comment designed to shock - in fact, it's old news - but the latest rundown of earnings published by The Hollywood Reporter may heighten your frustration all because of one name: Robert Downey Jr.

Downey Jr. may not be one of the highest paid actors currently working in Hollywood - that feat goes to Jennifer Lawrence, Will Smith and Dwayne Johnson who will all net $20 million (£15m) for upcoming films Red Sparrow, Bright and Jumanji sequel Welcome to the Jungle - but he's not far behind.

For his work in this summer's buoyant Marvel outing Spider-Man: Homecoming, Downey Jr. pocketed $15 million ($11.2m), an infuriating revelation when considering his appearance as Iron Man alter ego Tony Stark served as little more than an extended cameo clocking in at just under eight minutes. Staggeringly, that's - wait for it - around $1.8m (£1.3m) a minute.

Writing about an actor's salary may seem futile, especially when the very notion of even caring feels like an increasingly rote exercise. Disney may have roped him into contractual obligations eliminating his opportunity to star in much else out of the Marvel Cinematic Universe (his Iron Man appearances currently sits at eight) but his once-engaging screen presence and proven capability in delivering performances of heft (Chaplin, Wonder Boys, Zodiac) has clearly been eroded away by the influx of dollar bills.

The point is this: when you're getting paid $15m for less than 15 minutes of screen time, why would you still bother? Downey Jr.'s Spider-Man: Homecoming wage is emblematic of a deep-rooted industry problem - these actors get hired for being both skilled in their craft and well-liked. Keep paying them the big bucks, however, and they'll ultimately lose what won them the role in the first place.

Fortunately, one day soon, RDJ will lay his Iron Man suit to rest - and his inevitable descent down the Hollywood salaries lists will elicit more emotion from me than any second of his $1.8m-a-minute cameo ever could.