Shadow and Bone had the difficult task of adapting Leigh Bardugo's Grishaverse books to the screen. Luckily, it seems that the writers of the show are more than up to the task. Some might suggest that the show is even better than the books due to some of the changes made by the show's writers. The Shadow and Bone books follow Alina Starkov as she discovers that she is a Grisha or a person with magical abilities. She realizes this due to traveling through the Shadow Fold with her regiment and Mal's. When a volcra almost kills Mal, she lets out a burst of light and saves her friend. Unfortunately, this attracts the attention of the Darkling, known as General Kirigan in the show, who questions Alina about the situation. Alina is accused of being a Sun Summoner, a kind of Grisha that is thought not to exist anymore.
The Darkling uses his Shadow Summoner powers to confirm if she is indeed a Sun Summoner. He then arranges to have Alina brought to the Little Palace in Os Alta to keep her safe. While they're on the way to the Palace, Fjerdan assassins attack them. The Darkling saves Alina from one of them and takes her the rest of the way to Os Alta. Once at the Little Palace, Alina meets a tailor named Genya, who makes her presentable before she meets the King and Queen of Ravka. The King and Queen then meet her, and the Darkling helps her show off her sun summoner abilities. This much is the same in the show, though the Darkling mostly goes by the name General Kirigan. However, there are some details about Alina and the story that the show changes.
In an interview with Variety, showrunner Eric Heisserer describes Alina as a protagonist. Though she is somewhat of a chosen one, she doesn't want to be. In his words, "she feels like it reduces her as a person to a purpose and nothing more, and that it puts her on a pedestal for so many people. And she knows what happens when you're put on pedestals; you're gonna get shoved off sooner or later."
Alina constantly questions how she fits into the world when she becomes the Sun Summoner. Heisserer wanted there to be an even greater internal conflict for the protagonist. Therefore, he decided to make Alina even more of an outsider prior to discovering her powers by making one of her parents from Shu-Han, a Grishaverse version of China and an enemy of Ravka. Luckily, author Leigh Bardugo agreed.
Heisserer also thought that making Alina basically half-Asian would also connect her story to the characters of Six of Crows, which are more diverse. Heisserer also changed the show from the books by adding the Crows. While the Shadow and Bone books focus primarily on Alina and her story, spinoff books Six of Crows and Crooked Kingdom tell the Crows' story. Kaz Brekker, Inej Ghafa, Jesper Fahey, Nina Zenik, Matthias Helvar, and Wylan Van Eck make up the Crows.
Wylan has not been in the show yet. However, the show does include most of the Crows. The Crows are the exact opposite of chosen ones. Some people at Netflix weren't sure about the Crows, but Heisserer said they would ensure the show's long-term success. After some discussion on how to interweave the two separate storylines, Bardugo happily agreed to have the Crows appear in the Shadow and Bone story.
The Crows certainly add a lot to the Shadow and Bone show. They might be some of the most interesting characters. They add a much-needed element of fun to the story and the diversity that is mentioned above. Having Alina be half-Shu and, therefore, more of an outsider before discovering her powers also adds a lot to the show. Not only does it add more diversity, but it also makes fans feel for Alina in a way that perhaps they wouldn't for her book counterpart. It makes her holding on to some sense of normality so hard make sense in a way that maybe it didn't in the books. Fans who watched the show first or who have only watched the show probably couldn't imagine the story without these changes made from the books. While fans of Bardugo's books will likely have differing opinions on the show's version of events.
Of course, not every fan will prefer the show's version. Some will prefer Bardugo's takes on the characters and events, which is fine. Everyone has different tastes. Yet it is somewhat difficult to imagine the show for Shadow and Bone being any different. After all, the Crows are intriguing characters and Alina's part-Shu heritage is a big part of the plot.
Without these changes, the show might not have appealed to non-book fans as well as it did. Though of course, opinions on that will differ as well. Some fans might feel the show's writers should have stuck to the books more closely, which is fine. Every preference is equally valid. Fans will always disagree, but that doesn't mean that other preferences can't be understood.