Some characters in stories are obvious devices to make the plot go in a certain way, instead of being actual characters. They serve as a very interesting example of how personal taste matters-people who agree that the characters are there simply as plot devices can still disagree on whether or not that damages the actual story or not.
In my opinion, I view an overabundance of plot device characters as a big problem in Worm. Without spoiling anything, there’s one character notorious for having the most blatant and ridiculous plot-device power imaginable, but most of the others still have it to some degree or another.
Then again, because I never got into the immediate prose of Worm, I notice small issues like that in outsized terms. So it’s back to personal taste, I suppose.