Saitama is basically the only adult in the room. Half of the characters are brain dead in their pursuit of power, half of the characters are too much into scheming. Saitama is just normal guy with common sense.
I don't think One is that much involved with writing. Granted his writing has...
Unlike the previous work, this one seems to be more consistent during the whole story. Hope it lasts that way till the very end - granted we are close.