The Last Tycoon: More than meets the eye?

Okay, so I finally got around to watching 'The Last Tycoon' (1976). I know, I know, it's not exactly a hidden gem, but as a Fitzgerald fanatic, I had to check it out eventually. And… I'm left with a bit of a weird feeling. It’s… fine. Robert De Niro is great as Stahr, of course, capturing that almost manic energy that Fitzgerald wrote so well, but I'm not entirely convinced the film really gets him, if that makes sense? The book paints Stahr as this flawed genius, driven by both ambition and grief, but the movie kinda flattens him out into… just a workaholic with a crush? I think Ingrid Boulting (Kathleen Moore) is miscast as the object of his desire. I didn't 'get' the Stahr's obsession from that casting. My theory is that the movie shies away from really digging into the darker themes of the novel. It's almost too focused on the romance angle, at the expense of exploring Stahr's self-destructive tendencies and the corrupting influence of Hollywood. Remember the scene where Stahr is directing that silent movie and he just knows what the audience wants? The film shows that, but it doesn’t communicate the almost scary level of control and influence Stahr has, and how that’s connected to his eventual downfall. Why do you think that is? Was it the filmmakers afraid to 'go there'? Also, anyone else feel like the ending was rushed? The book has this really powerful, almost dreamlike quality as Stahr spirals, but the movie just… ends. It's like they ran out of time or something. I think maybe they tried too hard to make Stahr sympathetic, which ultimately robbed the story of its bite. I'm going to have to reread the source material to better formulate my thoughts on this adaptation. Anyway, that's just my initial take. I'm really curious to hear what other people think. Am I missing something? Did anyone else feel like the movie pulled its punches?