Part of the phenomena is manufactured and designed to be reductionist.
Is there's a demographic for princess manhwas? Yes, but also for trans-humanist sci-fi, for world adventure, for crime mysteries. An aspect I don't like abt WT or Tapas is the thematic separation of company originals and the indie creators. This isn't about acquisitions (which I feel is predatory anyway), but there's a clear divide between what genres that get respect.

The main comic UI obscures additional genres (BL, GL, LGBTQ+). You can access the came categories plus comedy, but does not list other categories.

However, the community/indie comics have additional categories at the end. The navigation bar does not span the width of the site. Aside from the vague word choice (community makes me think of forums or the company's about section), these categories being at the very end intentionally obscures and separates them. I need to confirm if this is the same issue on mobile.
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Romance, for example, can be advertiser friendly and watered down; there's more monetary incentive to write something with a simple, non controversial premise drawn in an art style people can emulate. At best, there's a lighthearted, relatable series. At worst, there's lackluster work that carelessly excuses poorly written stories as tropes for the genre (heavy on Lore Olympus). There's a way to integrate darker themes in romance, but if the author has to make characters besides the love interest uninteresting, that isn't enough to make the main characters interesting either. Not everyone needs to be grand, but at least have appeal/depth.
Slice of life is able to get away with this because we're already aware of the qualities of the genre; non-linear. This works for web comics or newspapers because people can infer what the story is about without having to follow from the start. I don't have to read Garfield from the start to get what it's about, nor do I have to rot my teeth to keep up with Bazooka Joe.
Beyond genre, I just feel many web comics are designed to have so much filler so people can stay on the page longer.