While this may be a surprise to some people, most authors are not prolific enough to live off of writing. Writing doesn't have to be your profession, it can be a side project you work on. So feel free to write even if you can't become a "full time" author.
Honestly, if they removed terminology like hp and just say that it slowly saps his life away then it could be a straight fantasy instead of having unnecessary game elements.
Yeah, but you can't kill an earthquake to prevent it from killing more people. Killing Muzan stops him from killing or creating more demons. It's kind of a stupid argument.
@Raine_Lane
It's a comedy. Him not realizing it is all real is the premise the story is revolving around. He probably won't realize it was real until the end of the story, if he does at all.