Man, this deconstruction of fear and heroism is genius
2 faces of the same coin:
Adoration
Fear
Devils gain power from being feared, and must commit acts of evil to force humans to fear them in order to stay powerful.
Chainsaw Man, choosing to walk the path of the Hero of Hell, must tiptoe the difficult tightrope of the anti-hero, saving devils and humans, but making sure that they fear him in order to remain powerful enough to do just that, save people.
Much like the great leaders of revolutions past, or even just law enforcers and vigilantes of today. Fear is useful. Fear may be used for the greater good.
Chainsaw Man>Batman