The admirals, but I believe it was the One Piece fanbase itself that exaggerated these characters. People wanted the TOP TIER characters of One Piece to be treated like gods, believing that the commanders couldn't stand a chance against them, that the gap between them and commanders was insanely huge. Then came the Marineford War where they woke up to reality. However, instead of accepting what the author showed, they created layer upon layer of excuses like: "It's because the admirals were restricted", "The admirals were just playing around".
Then came the Yonkous Kaido and Big Mom post time-skip, who brought a completely abnormal and never-before-seen aura to the manga, true monsters where logic didn't seem to apply.
However, Big Mom ended up facing problems due to being too strong, and Oda decided to draw a parallel between Roger and Luffy, with both sneakily grabbing Big Mom's Road Poneglyph and escaping.
In Luffy's case, he was too weak to face such a strong opponent, and this idea lingered for a long time. Then Oda began to exaggerate with new powers like Future Sight, and Conqueror's Haki, and awakening reached such an extreme point that there were idiots claiming that all admirals and Yonkous would have it. In summary, we even have gods occupying the status of Yonkou, and indeed the Yonkou are superior and receive a treatment befitting monsters, however, the admirals are greatly unjustly treated and don't measure up.
The Yonkous defy logic:
- Blackbeard shocked everyone and broke the logic that if you try to consume two Devil Fruits you die
- Whitebeard had powers with the potential to destroy the world, and there's a good chance he belongs to the same race as Kuma, who now possesses a mysterious power in addition to enormous physical strength.
- Big Mom was killing giants at 5 to 10 years old, giants and bears. She was born as a complete anomaly with an indestructible body and superhuman strength.
- Shanks is the author's self-insertion into the manga.
- And Kaido's existence is so formidable that it's almost indescribable to talk about him. He's referred to by one of the Four Emperors, Big Mom, as "that thing," feared by everyone. He's the strongest living creature in the world, the best individual fighter in the world, he's a demon, and he possesses a Mythical Zoan that allows him to transform into a legendary creature like a dragon. On top of all that, he was born with a power possessed by only 1 in 1 million, and he can use it in an advanced way.
- Luffy is the one destined to be the Pirate King, he is Joyboy, possesses a Devil Fruit of a mythical god, etc., and he is an Emperor.