Cosy Rhodes won the big belt at wrestlemania. Culmination of years long story build up in and out of character.
He was a wrestler with a legacy of being the son of one of the most beloved American wrestlers (Dusty Rhodes who has a pretty iconic speech about economic hardship.

Despite that legacy (or because of it) he was treated like shit by WWE, he left and ended up being part of another company (AEW) that started to position itself as a competitor to WWE. He got big there because he's good at what he does. After some time and some big storylines he came back to the WWE, now as a big name. Still not taken completely seriously at times, but as Vince McMahon gets sidelined more and more, Cody Rhodes gets to be bigger and bigger. A storyline has emerged: Codys father Dusty never got to hold the WWE championship, despite being a massive name. Cody needs to get the championship to finish the story or something. I haven't been following along very well, but this is what I've picked up from sporadic watches.