I would disagree. OPM was originally about Saitama’s ennui from getting so strong nothing excites him any more. There was the standard Japanese posturing as well because no one knows how strong he is, but it always came back to Saitama being a hero for fun, but it wasn’t fun anymore. It all came to a head with the Boros fight, when it looked like Saitama finally met someone he could play with and who shared his melancholy at being so much stronger than everyone else before it’s revealed Saitama was doing him a favor by pretending it wasn’t just a one sided fight.
Everyone else went from being some aspect of seeking strength or following justice to being the focus of power level fights between the heroes and monsters.
The story isn’t about Saitama living with his overwhelming strength anymore. It’s the fucking z fighters holding off the villains of the arc while they wait for Goku to show up.