It is interesting to see how trailers have changed over time. I recall a few decades ago, they would have fairly long sequences but with a loud, urgent, voice-over narration in the annoying style of old newsreels. Take this one for The Bridge on the River Kwai (1957).
These days that obnoxious narrator is gone, to be replaced by an occasional and more subdued voiceover. But now the trailers have annoying rapid-fire cuts that last for very short times. The goal these days seems to be to show a fraction of every scene of the entire film in the hope that at least something will appeal to the audience. I have got into the habit of playing a game in which I try to identify which bit comes from the climactic scene of the film. Here’s a trailer for one of the Pirates of the Caribbean films.
No doubt these trailers are the products of extensive market research but I wonder if showing a few scenes in more depth in the old style (but without the old narrator) might engage the viewer and cause them to want to see the film more than these scattershot montages.