Tapas started off only doing webcomics. Apparently webnovels are relatively new here. People also are more willing to sub to comics then novels. My best example is Beginning of the end. The comic has way more subs than the novel despite the latter existing for longer.
Everyone who was sub to the novel would have gotten a notification when the comic came out wo there's that. And then some people might choose to avoid reading one so they can read the other without anything being spoiled.
If you look at the front page there's two location novels will be promoted. Staff pick and community pick. Only one of these has a novel exclusive version. There's also five time the amount of comics than novels. New and noteworthy can promoted novels but I think I only seen that once or twice. But I have only been here since April.
I know Tapas has said that they are working on more ways to promote people but I have no clue what's in the works for novels. 🤷‍♂️