Rafael

Brother, sure and yes, Deku did all that, but, like you said, All Might is still more famous.

He was an OP hero for around 40 YEARS, beating the shi- out of villains both in the US AND Japan, maybe even more. 40 frickin years. He marked TWO generations at that point. It will never matter who Deku defeated because everyone, INCLUDING CLASS 1-A THEMSELVES, will always remember All Might and his greatness saving cities throught those famous countries.

Deku, on the other hand, was barely known. He did indeed beat the greatest villain and save the world, but the world itself never recognized AFO and Tomura as threats to it, the governments yes but not the people. So, when the world saw the battle on tv, they saw Class 1-A, and Deku as part of it, so they glorified that class.

But that's the thing, although Deku did save the world, in that war, only other heroes were at all while watching him and knew his greatness, and the world just saw that one day. Deku saved millions of lives INDIRECTLY, while All Might saved thousands of lives DIRECTLY, that gives a much bigger impression on people. He then lost OFA, spent the ambers in the rest of school time, and spent 8 years as a teacher before returning to his hero career. The world KNEW that happened, but it wasn't really that recognized. We even saw in one of the extra panels that he was seen as a legend by a kid, amazing but not really believable. The whole class ended up being glorified, but, due to Deku's lost of power, his fame wasn't solid. But Deku doesn't mind because he much prefers sharing that title, reason why, at the end, he changes the name of the story to "The story of how WE became the greatest heroes!"

Deku beat the strongest villain and saved the world, but All Might has been a hero for faaaaar longer and even shaped the current heroes and Deku himself. His legacy and his influence are what still make him the greatest hero and Class 1-A are the ones inheriting his glory, and they have only just started.