The Lord of the Rings books and movies follow some rather unconventional protagonists. Even Frodo Baggins (Elijah Wood) himself is not a typical hero. Nor are his friends Samwise Gamgee (Sean Astin), Meriadoc Brandybuck (Dominic Monaghan) also known as Merry, and Peregrin "Pippin" Took (Billy Boyd).
The Hobbits are not in any way stereotypical fantasy main characters. However, that is part of the charm of Lord of the Rings. The Hobbits are very special characters, and definitely have great arcs throughout the story, particularly Frodo. What is it that makes these Hobbits such good protagonists? Well, it's a combination of several factors, really. Before getting into what makes the Hobbits so good, it's important to understand their arcs. Frodo's arc is mainly about going from an innocent Hobbit to an older Hobbit who knows the reality of the world.
Essentially, the point of Frodo's story is him growing up. However, it is also important for him to remain hopeful. Someone who helps Frodo remain hopeful and believe in the goodness of the world is Sam. Sam is not the most confident of Hobbits, at least at the beginning. Yet he is a good and loyal friend to Frodo. He is always there for Frodo, refusing to leave even when Frodo leaves the Fellowship. He is there for Frodo until the end, helping Frodo get to Mordor and get out of Mount Doom. Sam is consistently loyal but he also gains a lot of confidence throughout Lord of the Rings. Merry and Pippin have similar character arcs, which makes sense since they are very close friends and have a similar role in the story. In the beginning, they're mostly comic relief.
Yet both Merry and Pippin have hidden depths. Merry is a rather intelligent Hobbit, especially in the Lord of the Rings books. He knows from the beginning that the Ring is powerful. In the books, he and Sam, Pippin, and Fatty Bolger are determined to help Frodo. Of course, he and Pippin both become members of the Fellowship. After they are kidnapped by Uruk-hai, Merry and Pippin manage to escape when Eomer and his men attack the Uruk-hai. Merry and Pippin run into Fangorn Forest, where they meet Treebeard, an Ent. They convince him and the other Ents to attack Saruman and are left to guard Isengard after Saruman is defeated. Merry meets and begins to serve Théoden, the king of Rohan. He accompanies an unknown soldier to battle.
Of course, this unknown soldier ends up being Eowyn. He helps her defeat the leader of the Nazgûl, the Witch-King of Angmar. Therefore, Merry gains some courage throughout the story. He ends up being much more than just a funny sidekick. Pippin, too, gains something. He, like Merry, is kidnapped by the Uruk-hai, and Boromir attempts to defend them. He, along with Merry, convinces the Ents to go to Isengard and guards it with Merry. Pippin picks up the Palantir and has an encounter with Sauron himself, which leads the Dark Lord to believe that Pippin has the Ring. For his protection, Gandalf takes him to Gondor, where he meets Denethor, the Steward of Gondor. He pledges to serve Denethor and becomes a Guard of the Citadel.
Pippin witnesses Denethor attempting to burn his son Faramir alive, but thanks to Pippin's quick thinking, he and Gandalf are able to save Faramir. Therefore, Pippin too gains courage and a bit more intelligence and maturity. Pippin, much like Frodo, grows up. So what makes the Hobbits such good protagonists? Firstly, they are underdogs. Because they're not typical fantasy protagonists, they are underdogs because of the huge threat they face and how they're perceived by the audience. What hope does a Hobbit seem to have against the huge army of Sauron, against the Dark Lord himself? It is precisely that tension that makes Frodo, Sam, Merry, and Pippin so special. The Hobbits in Lord of the Rings are also great protagonists due to how deeply emotional they are. This helps fans feel for them even more perhaps than other characters.
The Hobbits in Lord of the Rings are also good protagonists due to their well-written character development. None of them end the story the same people they were at the start. They grow and change and fans get to see it all. Of course, not every Lord of the Rings fan will agree. Some might not find the Hobbits that exciting, or will have different reasons for appreciating them. That's fine, everyone's different. Yet the Hobbits of Lord of the Rings are certainly good characters. The story wouldn't be the same without them. Without Frodo, Sam, Merry, and Pippin, Lord of the Rings would be a different story. And that's definitely a sign of a good protagonist. A protagonist that can be taken out of the story without changing it would not be good at all. Yet that's not the case here, so the Hobbits are probably very good protagonists.