The new film The Killing of a Sacred Deer is not for the faint-hearted or indeed the faint-prone. Its title refers to the Greek mythical animal owned by Artemis and killed in error by Agamemnon, who then has to sacrifice a member of his own family to appease the goddess.

In the film, cardiac surgeon Steven Murphy is our contemporary Agamemnon, which makes Nicole Kidman’s character, Anna, Clytemnestra. The brutality, however, is ancient – straight out of Aeschylus’s Oresteia. It is an intense and challenging film. I left the cinema slightly numb with shock.

I realise that I quite often leave films with Kidman in them feeling slightly numb with shock. Lars von Trier’s Dogville, say, or Jonathan Glazer’s Birth. Kidman has worked with some of the most idiosyncratic and exacting directors of her generation. In these films, she regularly turns in what is described as a “career-defining performance”. But, somehow, her career never ever does emerge “defined”.

Her co-star in Sacred Deer, Colin Farrell, has a more “defined” career than Kidman does. He is considered an important actor as well as a big star. Yet Kidman is an important actor too. She is singularly brilliant, prodigiously talented. Of course, this was acknowledged early on, when she starred in Philip Noyce’s psychological thriller Dead Calm and hit international pay dirt in 1989. She’s now Australia’s wealthiest entertainer. Kidman’s career is nothing to complain about. Yet, still, there’s a feeling that she isn’t taken quite seriously as a creative behemoth. Or maybe it’s just me.

I rolled my eyes, along with much of the rest of the world no doubt, when Kidman stood on the stage at the 2003 Oscars and declared that Hollywood was there despite the Iraq war “because art is important, because you believe in what you do”. I laughed at last year’s diamond ring-protecting “seal clap” too. I know far more than I should about Kidman’s romances, marriages and children – information I seem to have gained by osmosis. I’m perfectly happy to speculate about how the hell Kidman manages to look so “flawless at 50”. Yet this is all just packaging. Hollywood actors such as Kidman (female) are treated far more as packaged commodities than their male counterparts are.

I think it’s a problem that is particularly intense in America and specifically Hollywood. It’s relatively easy to name great British female actors – Judi Dench, Helen Mirren, Maggie Smith, Kate Winslet, Emma Thompson, Rachel Weisz. They’ve all had success in Hollywood, yet their reputations rest on respect of their work above all else. But it’s a struggle, putting together five actors from across the pond with similar status, even though there are so many more to choose from – maybe Jane Fonda, Jodie Foster, Sigourney Weaver. Maybe. Or maybe Hollywood only allows itself one unquestionably great female actor at a time. If so, it’s been Meryl Streep for ages.

It’s this hard-to-define discrimination in artistic status that I think dictates the Hollywood pay gap. The idea is that women stars aren’t “box office” in the way that male stars are. The reality is that the entire machine primes audiences to view female actors as lesser in status, and therefore pulling power, than male actors. As for the “casting couch”, this has to be seen as a particularly loathsome method by which female actors are marked as commodities from the start of their careers. The fact that the liberal community of Hollywood kept the lid on it all for so long simply confirms that such appalling tactics work.

It’s remarkable, also, that Kidman is still famous for previously having been married to Tom Cruise. Her career puts that of her long-ago ex to shame. Yet, despite the pervasive whiff of creepy weirdness about Cruise, who discarded Kidman as if she were some white-goods item that had stopped working, his own place in some mythical, and baffling, pantheon of the greats remains assured.

I can’t help feeling that with both her superb performance in the television series Big Little Lies, and her choice of Yorgos Lanthimos’s Sacred Deer, which manages to explore the politics of gender with subtlety and crashing force combined, Kidman is gravitating towards roles that place women in situations where they become complicit in disguising the status-hungry and abusive manipulations of their men. She’s one to watch. You read it here first.

• Deborah Orr is a Guardian columnist