In Jump messages Oda literally talks about how his main goal in life is world peace and promoting equality.
He’s never gonna portray an admiral as threatening for the remainder of the story, since they’re literally just jobbers for Oda to self insert his own message into the story.
You literally have Shanks (literally Oda’s self insert) embarass Greenbull (literally a walking meme of what Oda’s against).
It’s straight up a “the good guys are strong because they’re good and the bad guys are weak because they’re bad” trope so that Oda can spread his message.