Murder solved. Now solve Poirot + Problem with adaptations

Rating: 6/10 (29 July 2019)

Admit I don't recall the original, but I'm guessing when Agatha Cristie wrote this masterpiece, Poirot wasn't exactly famous, and he wasn't introduced as such in the book.
That's the anchor that keeps this adaptation of the story firmly in the same spot and doesn't allow it to move one inch, despite the remarkable twists, theme and design of the narrative.
Problem is even if one accepts the coincidences surrounding the simultaneous appearance of all this pour souls on the same train, along with the killer who destroyed their lives, which of course is later proven that is anything but a coincidence, the presence there of, as he so eloquently phrased it, probably the best detective in the whole world, and one that in the year we live in everyone knows, completely destroys the story. Missed the first five mins, and I don't know whether the killer hunted down Poirot to ask for his help, and that's how they got on the same train, but even if that's the case, I don't see it making much sense.
I mean they managed to get the killer on the train and booked the whole trip to extract their revenge, and they invited along the only person in the world who could solve the crime. That's just trying too hard ...
Maybe a better adaptation that better suits our time would've been to start from the ending of the film. A detective calls the FBI or whatever and basically surrenders the case. I have a train full of people and a murder case I cannot solve. Please help me. And a team arrives, among whom there's a really talented young detective that manages to find that these people are connected somehow. Then break down the story in reverse ... If you have to keep the train I mean.