I’m actually really hyped for the 18 routes, tbh.
The whole theme is about the characters. The whole essence of the world fascinates me: a place where young people who died early are sent in order to find meaning in their lives and be ready to move on to What Comes Next. Reference my other post for more details.
It’s literally centered around the characters. So of course you’re going to want to spend more time with them; that’s the whole point. It’s a series of stories of how people with broken lives and hearts found meaning and happiness. Instead of writing 18 stories set in that world, he writes one episodic VN with them all included. It’s an all-you-can-read buffet of those kinds of stories.
It’s similar to why Umineko had the same story of murder replay itself again and again: people like those stories! People want to read more about people being murdered in locked rooms! So instead of trying to rewrite that kind of story, Ryukishi07 went for a story where he could write variations of it over and over. It was brilliant and satisfying. And yet mystery buffs still want more, even after that.
Speaking of Umineko, I really liked how they did multiple “routes” of the same story, even though it wasn’t a route you chose. They tied the different series of events into the main narrative and made all of them happen (with the meta world and all that). It was really neat; I much prefer that over something where the side routes aren’t canonical and didn’t actually happen. Though it’s hard to reconcile that in other kinds of stories.