Ariel has always been a plucky, badass heroine, but the 2023 movie really drives that point home by having her do some of the things that other characters did in the original cartoon. It might be the best overall change between the two versions.
–She tricks the shark that attacks her and Flounder with a mirror so that they can escape. In the cartoon the shark gets stuck in the ring of an anchor by accident.
–During “Kiss the Girl,” she figures out how to tell Eric her name without anyone’s help. Sebastian just whispers it to Eric in the original.
–She physically fights Vanessa/Ursula to get her voice back. As in, Ariel runs up to her, tackles her, yanks her necklace off, and throws it on the ground. In the cartoon, the necklace falls off Vanessa thanks to Scuttle.
–And finally, the movie reverses Eric and Ariel’s positions during the final fight against Ursula. This time, Ariel steers the boat that skewers Ursula.
Source: https://www.buzzfeed.com/evelinamedina/little-mermaid-remake-best-worst-changes