2021 has been great in terms of Korean productions as exemplified by "Sweet & Sour" and "Move to Heaven". "Hellbound" is a series for everyone, but not everyone will appreciate it.
The title and the reactions in the series to a repeated supernatural phenomenon, gives the viewers an insight into mass psyche in front of God/the transcendent.
Then, in the middle of the series one person makes a smart remark that goes against mainstream: in reality we are facing an unexplained set of phenomena and some people are exploiting these phenomena.
The author and/or movie maker will make everything crystal clear in the last seconds of the last episode, and I won't spoil it.