Sure, they are. They play important roles and their relationships and adventures are part of the comic's established canon. There are many story arcs featuring them both.
Betty and Jughead's relationship in the comics is complex. Sometimes they are together, but there are also times when they face challenges or are not in a romantic connection. It all depends on the plot and character development within each comic issue.
One characteristic is that it often focuses on their complex relationship. In Riverdale, they have a unique bond that fanfic writers like to explore. Another is the mystery element. Since the show has a lot of mysteries, fanfics may incorporate those into their stories about Betty and Jughead. For example, they might be solving a mystery together while also dealing with their feelings for each other.
The Betty and Jughead kiss in fanfiction can vary greatly. Some fanfictions may depict it as a spontaneous act, while others might build up to it over a long period of time. It could be a turning point in the story, leading to new developments in their relationship, like facing challenges together or growing closer as a couple.
Jughead and Betty did have a dating phase in the comics. It was a significant part of their character development and added depth to the overall story.