I agree with Pierre Bayard that literature – he goes further & says culture – is a ‘system’ before it is individual books, individual poets, individual poems. Which is what I mean when I say that there is no such thing as a poet, there are only kinds of poets. It’s not about what you write – it’s about location, location, location. What you write is what gets you into (or out of) a particular location. I know it’s not how it feels when you or I write a poem, but that is the overarching social dynamic that takes place. One of the reasons I keep putting in links about English-language poetry stories from such diverse places as Nigeria & Pakistan is because I want to understand now what the world of my poetry is going to look like just a few decades hence, when such poetries are as much a presence in the then-equivalent of Jacket as Australian verse is now...
As I’ve argued before – and no doubt will be forced to again – poetry’s role as a carrier of narrative declined markedly with the rise of the novel. An alternative had come along that handled narrative far more efficiently. The form of the novel was explicitly designed to do so. And the history of the novel is that it too has struggled once cinema arrived because the novel's social necessity was then taken over by the flickering screen. To what degree today are novels (& especially short stories) simply plot ideas for screenplays? Quite a bit more than we might be willing to admit. This is why the ‘traditional’ novel has declined markedly, to be replaced instead by its own School of Quietude (Bellow, Cheever, Updike, Roth) on the one hand, and a series of genre alternatives, each of which is driven by the needs of its specific genre. In addition to the usual genre alternatives, sci-fi, romance, porn, such fields as ‘experimental’ and even ‘Oprah’ (aka ‘book club ‘) fiction all thrive – it is only the ‘serious, traditional’ novel that is in its death throes.
I don't know whether "efficiency" is the right word to describe the novel's displacement of poetry as a vehicle for narrative (or for film's subsequent dislocation of the novel) -- unless we're able to think about "efficiency" not as something wholly intrinsic to the medium itself, but in the context of social or systemic necessity.
Poetry (particularly epic poetry) does different things with narrative than the "traditional" novel does. If you're a fluent producer/consumer of the shape/dimensions/social context of narrative that poetry provides, then it can be an absolutely superior way to consume narrative -- at least particular kinds of narrative. It's just that the vast majority of us are no longer fluent in this mode of narrative; we've all coordinated ourselves and our aesthetic expectations around (first) the novel and then cinema.
In technological studies, this is called path-dependence. The longer you use something, and the greater the social coordination costs and returns, the more efficient a technological network becomes, not because of its inherent efficiency but because the costs of switching become too high. It's like trying to switch from a QWERTY keyboard to some other system. Sooner or later, the kids are banging out text messages with their thumbs, but it takes a lot of time.