The Straw Hat Pirates are at the core of Eiichiro Oda's One Piece and the story follows their adventure all the way from the East Blue to the Final Island, Laugh Tale, and potentially even beyond. Luffy, the captain of the crew and the main character, is, undoubtedly, the most important person in the story and as he began his journeyed from Fushia Village, he amassed quite a powerful crew.
Gathering the likes of Zoro, Nami, Usopp and Sanji from the East Blue, the group headed into the Grand Line where they further recruited Chopper, Nico Robin, Franky, and Brook. Taking two years to get stronger, Luffy and the group set sail for the New World where they managed to get one of the former Shichibukai, Jinbe to join them. While all of the Straw Hats had a personality of their own before meeting Luffy, he certainly did have a profound effect on all of their lives.
The Effect Luffy Had On The Straw Hat Pirates
The start of Luffy's journey was a clear indication that he was, in fact, a person who brought everyone together. Right from the very beginning of the story, Luffy helped those he felt needed it and freed them from oppression and tyranny. As such, a character like him inevitably changed lives for the better. For instance, as soon as Luffy set off on his journey, he saved Koby from Alvida's tyranny and inspired him to chase his own dreams. Years later, Koby still holds Luffy in high regard despite being a direct rival to him. While Luffy has affected thousands of lives with time, he's touched the hearts of the Straw Hat Pirates the most.
In his own way, Luffy has affected the lives of every single member of the Straw Hat crew. He's given some a reason to fight and push forward, such as Nico Robin, and saved others from impending death, such as Roronoa Zoro at Shell's Town. Luffy has filled the broken hearts of the likes of Chopper, who was ostracized by humans and animals alike and went to the depths of hell to save his friends. With Jinbe, he's earned his respect and shown him that he's capable of bringing forth the dawn of the world and fulfill the dream of Queen Otohime and Fisher Tiger.
The Straw Hats' Lives Without Luffy
Without Luffy, however, the lives of the Straw Hat Pirates would've been very different. It wouldn't be a stretch to say that most of them would've been dead had Luffy not met them and saved them from inevitable death or freed them from their shackles. At Shell's Town, Zoro would've met his inevitable demise at the hands of Helmeppo's firing squad who were dead set on executing him. Just like Zoro, Usopp would most certainly have faced death when Captain Kuro unleashed his plan of 3 years on Kaya in One Piece's Syrup village arc. Sanji, on the other hand, would've lost his dream to protect Baratie, which he considered Zeff 's treasure from Don Krieg and his pirate crew and could potentially even have died. By saving him, Luffy not only gave him a new life, but also made him chase his dream of finding the All Blue.
In the East Blue arc, Luffy touched nobody's heart more than Nami, who he rescued from being a slave to Arlong's vicious rule in the Cocoyashi village. Had Luffy not met Nami, she would have never been freed from her burden and would eventually have lost all hope to live. In the Grand Line, Luffy's want to help those around him was just as strong, as seen when he rescued Chopper from his loneliness and extended a hand of friendship to him. Without Luffy, Chopper would always have had a hole in heart. In Alabasta, Luffy saved Nico Robin from death against her own will. What's more, he gave her a reason to continue chasing her dream of finding the Rio Poneglyph and unraveling the mysteries of the world before saving her once again in Enies Lobby.
While not as similar, Luffy also saved Franky from the clutches of the World Government and, what's more, from facing the same fate as Tom. Perhaps, Luffy touched Brook's heart the most as he rescued him from his loneliness of 50 years in the Florian Triangle. In doing so, he rescued Brook from a painful fate of staying alone forever. Despite him being a skeleton, Luffy offered him a home and called him a friend, which just goes to show that he doesn't discriminate. This was further cemented when Luffy took a liking to Jinbe and asked him to join the crew when the two shattered the prejudice between humans and Fishmen. In doing so, Luffy showed Jinbe that he would fight against racism and eventually make the world a better place, giving him another reason to stay alive.
While Luffy might not be the smartest of people, he is someone who values freedom the most. This quality has directly been tied to him since the very beginning of the story and now more than ever, following the reveal of the Hito Hito no Mi, Model: Nika. Over the years, he hasn't just affected the lives of his crew mates but countless other people as well. He is someone who spreads laughter, joy, and freedom, after all.