It's annoying when they stop abruptly and didn't deliver any continuation.
The problem can be solved by writing one-shot only, or write open ending that conclude every chapter by itself. Those kidn of stories force author to write proper conclusion.
***
Many author ovestimate how long they can kept making chapter, even after calculating their free time. Most people don't realize they're bad at math, nor do they expect huge writer-block when writing more complex parts of the story.
Writing by flow isn't making it easier. At the start of writing, writing by flow is easy as they won't have to stick to anything, just write as they wish.
Later on, they would start wishing that they already had a outline/draft for their writing instead of wasting time trying to fix the story right now, as the story suddenly have huge storytelling flaws, such as : overarching plot holes, bad delivery, and unexplained void.
And many also forget to write down the basic idea of their story only end up questioning and thinking deeply about the point of the story later on when the story start to look out of place and become cliched unrecognizable mess that's better left on Hiatus or just Abandon & Start rewrite already.