Last time I checked 19 Days was just something the author wrote as a hobby and not because she got payed for it which should explain why there isn't much plot going on.
I always read 19 days like skits. Just another day another stupid incident. However I do think there are several loose subplots developing. Such as Jian Yi’s familial problems. He Tian’s familial problems. She li and Mo’s problems.
The plot in webtoons like here u are or 19 tian does not develop at all. I want to read but I am bored...