Even in a continuing storyline, the webcomic comes in short concentrated bursts that have to have internal structure. Some merely carry on the story, but most have some kind of twist or turn that changes things. Reverses the appearance of things, reveals something, sends the plot twirling off in a new direction. Maybe it's twirled back that way it was two strips ago, but the continual shifting of possibilities keeps the story moving, in action, and interesting.
Paragraphs are too small units to require a twist in every one, though sometimes it's feasible. And scenes are often too long to have just one switch in them. . . the structure does not lend itself to the knowledge that something has to happen here.
You have to learn to pick it up.