It may have been 10 years since the last Twilight movie came out, but the series seems to be entering a Renaissance, particularly on TikTok. Fans are turning back to the books and realizing that they contained a lot more information than the famously-mocked films.
Film adaptations have a difficult job, adapting books that can take days to read in only a couple of hours. Things have to be cut for space, but the decisions made on what to highlight and what to leave off can make the difference between a Lord of the Rings-level adaptation and one like Eragon. The Twilight series chose to focus on romance to the exclusion of everything else, and it suffered for that choice. Adding more elements from the books could have entirely changed how the films were perceived.
The Significance Of Bella's Lullaby
Generally speaking, soundtracks are where movies are better than books. However, this doesn't work with Twilight, where Edward writes Bella a lullaby, which he then repeatedly hums to calm her nightmares and eventually makes into a CD. It becomes a representation of their love, and functions as a way for him to easily show her how much he cares.
In the films, the music theme is played at critical moments but is hardly ever discussed outright. One of Edward's most intimate and loving gestures fades into the background, becoming part of the scenery instead of the story. It wouldn't take much to make it a centerpiece of their relationship, but it would do a lot toward showing Edward's affection in ways other than throwing money around.
Bella's Head Injury After The Car Accident
Edward risks exposing himself when he stops Bella from being killed by a runaway van. However, in the books, she still ends up injured. Bella explains that her "head cracked against the icy blacktop," which leads to "a throbbing ache centered above my right ear." This becomes important both because it helps Edward discount her story and because, as discussed in Midnight Sun, it provides an excuse if the Cullens decide to kill her.
However, the injury doesn't happen at all in the film. Edward protects her from all harm, which makes it so she'd have to be stupid not to suspect something deeply unnatural was going on. In addition, the Cullens don't have the option to kill her, since there would be no excuse. Though it might seem like a small detail, it makes a big difference in how Bella and the Cullen family first encounter each other.
Tyler Being Possessive Of Bella
While many fans saw Edward as a borderline stalker in the Twilight movies, there's someone more possessive to compare him to in the books. After nearly killing Bella, Tyler Crowley becomes a little obsessed with her, inviting her to the spring dance and then assuming she will be his date to Prom.
The pair fall out after those events, which makes him a minor figure in the later books, but his persistence in the first helps Bella to work out what she doesn't want in a partner. Without him playing this role in the movies, Bella doesn't have as much of an opportunity to show off her agency in choosing Edward over other options.
Bella And Renee's Relationship
Bella's adventures happen because she came to live with her father in Forks. Although the movies largely seem to forget that Renee existed, the books show that Renee is still an active part of Bella's life, sending her regular emails and trying to make sure she is happy (even threatening to make her move away from Forks in New Moon).
In many ways, Bella was forced to be the grown-up when she lived with Renee, so moving in with Charlie allowed her to be a teenager for the first time in her life. This context is important to understanding Bella's relationship with her own daughter and would have helped establish who Bella was beyond her obsession with Edward.
Bella Gets Sick Around Blood
For a girl who is determined to become a vampire, Bella actually hates blood. In the first book, she gets extremely close to fainting in Biology class when they do blood typing, and describes it as smelling like rust and salt. This detail is left out in the films, but it actually does a lot of important work for the future of the series.
Not only does it connect with Bella being different from other humans, but it also shows just how much she loves her unborn child to drink blood in Breaking Dawn (though she does admit that it doesn't smell as bad as it used to). In addition, it may foreshadow her unusual control as a vampire.
Bella's College Plans
In the Twilight films, the vast majority of Bella's attention was fixed on Edward, as she whined and complained about everything else. However, she spent a good amount of time thinking about college in the books, where it became a metaphor for the human experience that she was so eager to be done with.
Despite having an interest in becoming a teacher when she grew up, Bella is incredibly resistant to the idea of applying to and attending college, even as Edward pushes it in Eclipse and Breaking Dawn. This metaphor could have highlighted the primary conflict of the series (humanity vs vampirism), rather than leaving more time for a love triangle that barely existed in the books.
Bella's Friends
In the films, Bella had few friends she actually cared about, with Jacob becoming a love interest and everybody else falling into the background. However, that doesn't line up with who Bella was. In Twilight, she had several friends, including Angela. Though she lost many of them during her depression in New Moon, she built new meaningful relationships with Jacob, Alice, and Jasper after that point.
Though Bella only considers Jacob romantically for a matter of chapters, she did sincerely care about their friendship. By eliminating Bella's friendships, she became a character with no personality outside of her relationship, and Edward and Jacob became fierce rivals, which was rarely the case in the books.
The Cullens' Backstories
Many fans will acknowledge that the best stories in the Twilight saga were connected to side characters, but few made it to the screen. This is unfortunate, because Alice, Esme, Carlisle, and Rosalie's backstories were very interesting and highlighted the various pros and cons of being human.
Book to film adaptations fail when they miss the point of the series, and Twilight was one of them. It was never about Bella choosing between the werewolf and the vampire. She made that choice extremely clear. It was an exploration of the importance of humanity versus the allure of immortality, with Renesmee representing the best of both. Taking away these backstories limited how effective that exploration could be.
Bella Figuring Everything Out
Finally, the Twilight films took away Bella's intelligence and cunning. In the books, Bella uses a combination of seduction and sly questioning the find out local legends about the Cullens, which leads to her discovery of the truth. She also figures out that Jacob is a werewolf in New Moon, though he did help her come to that conclusion.
In the films, she seems extremely oblivious, having to be led to any conclusions she eventually lands on. Had they taken more inspiration from their source material, Bella might have been a more interesting protagonist to watch. Instead, she became the primary example of a blank character and nearly convinced the world that Kristen Stewart couldn't act.