I know I had already written Sisyphus myth here, but here's a theory based on the myth:
"When Death came to fetch him, Sisyphus chained Death up so that no one could die. Finally, Ares came to aid Death, and Sisyphus had to submit."
What if the town is actually Sisyphus and Guwon IS death. He doesn't remember his past and the people in town say he can't die because he's the one that keeps everything at bay.
In chap 20 we get told "This place, Stillwater Town... was a refugee for those who ran from death."
And the image shown is of Guwon eating a person.
Let's continue with the myth:
"Before he died, Sisyphus had told his wife Merope, not to perform the usual sacrifices and to leave his body unburied. Thus, when he reached the underworld, he was permitted to return to 'punish his wife' for the omission. But once back at home, Sisyphus continued to live to a ripe old age before dying a second time.
The gods didn't like that Sisyphus played them like that, so as punishment Sisyphus was told he had to push a rock to the top of a mountain, but once he is almost at the top, the rock falls down again and basically all his work meant nothing, so Sisyphus goes down to do the same thing over and over again. A meaningless life basically."
The funny thing about this myth is that nobody really forces Sisyphus to do so, there is nothing pushing him to keep on doing this.
SO, if the people of Stillwater are Sisyphus in some metaphorical way, then that means nobody is really pushing them to stay, vote for another's death, etc. They just do it because that's what they think it's "the right thing" to stay alive, or in reality to evade the guilt for choosing to stay even though Guwon (death) has taken everything away from them.