It is obvious across the Rings of Power, The Hobbit, and the Lord of the Rings that Galadriel is one of the most remarkable elves in Middle Earth history. From the Peter Jackson movie adaptations, it was clear that she was both wise and powerful, and a great leader to her people in Lothlorien. But the Rings of Power series has shown a whole new side to her personality, one that listens to her own voice over the voice of others that try to drown her out. She defies the gift of returning to Valinor because she knows in her heart that there is more at stake than her own peace of mind. And she is able to convince the queen of Numenore to ally with her and set sail to protect the Southlanders that are being overrun by orcs.
As a part of this journey, Galadriel also displays that she has incredible swordsmanship. Viewers learn in Episode 5 that she can handle a blade better than most of the trained guards of men. But why does she never use this skill in the Lord of the Rings? The answer is because of the one ring itself.
During the fifth episode of the Rings of Power series, Galadriel is seen training with the men of the sea guard, at the behest of Elendil. It is clear that he knows of the elven grace and ability when wielding any weapon, so he prompts her to show the boys how it is done. She starts off one on one, effortlessly dodging and gliding around her opponent. As more and more of the sea guard begin to attack at once, she misdirects them into walls and each other. She strikes with her own blade and catches killing blows at their throat (without harming them), and she manages to defeat the lot with barely a scratch to her dress. For such an incredible warrior, there can only be two reasons that she is never seen to fight like this in the later movies.
The first is that there were actually several epic battle scenes that were removed from the final cuts of Peter Jackson’s films. Such scenes included an amazing fight showing Eowyn defending the glittering caves from a hoard of orcs, and of Arwen joining the fray at Helms Deep alongside Aragorn and Legolas. One of the biggest criticisms of the movie adaptations is that the portrayals of women lack of valor, bravery, and prowess, which is not the case in the books. In this sense, Galadriel is never given an epic sword scene in the films. Peter Jackson chose to portray her powers and strengths as ethereal, otherworldly magic, rather than a grounded, earthy weapon base. This can be seen in both the Lord of the Rings with her ‘drowned’ green appearance as she tries to resist the temptation of the one ring. It's shown again in TheHobbit as she fights the Ring-wraiths with her white flashes of light, and banishes the Necromancer into the East.
The second, more tangible reason relates both to the movies and to Tolkien’s original books. After the Second Age, Galadriel’s fate became much more tied up in the Rings of Power, and indeed the One Ring itself. The Amazon series is on the verge of Celebrimbor’s forging of the rings, an event that changes the face of Middle Earth forever. Once the 20 rings are made, all of the magic and the power in the world becomes tied, in one way or another, to the fate of the master ring. That includes Galadriel's.
Once she agrees to be the keeper of the elven ring Nenya, Galadriel's purpose in the world turns from warrior to protector. Her path no longer lies in great battles and revenge for her fallen brother. Instead, it now lies in keeping the ring safe at all costs, and preventing it from falling into the knowledge of the enemy.
The three elven rings are the most powerful next to the One. They are also the most pure, because Celebrimbor managed to forge them and hide them away from the poison of Sauron before the dark lord knew of their existence. Therefore, over the course of the Third Age, Galadriel's abilities in magic and in light grow immensely. She builds the beautiful woodland realm of Lothlorien, and defends it from the attacks around her lands during the War of the Ring. It is never stated that she no longer uses her sword skills, but it can be assumed that she no longer needs to rely on them as her only form of defense. She becomes a force to be reckoned with simply within her being and the phenomenal force that exists within.