The biggest problem with One Punch Man by far is the constant cliffhangers and cutaways during chapters.
Finally a chapter that kind of breaks that tradition. Kind of, because it still featured Saitama and Flashy Flash, albeit for a short time (and didnt finish the Garou fight).
Of course, Saitama is the protagonist, what Im saying is one chapter should focus on one theme. Like this one did (kinda), with good results.
Another problem, somewhat related to this is the number of different heroes, narrative threads. And of course, none of the heroes can die.
So the threads will just multiply and in numerous private battles, constantly changing, switching back-and-forth between battles.
So far, we have like six different and separate battles at the very least (atomic samurai, child emperor, zombieman, garou, tatsumaki, sweet mask), and those are just the battles.
Visually, the story is falling apart. The narrative will keep it together, but it is to the great detriment of the story.