I've been here since July 2020, and number 1 reason for this is because the end of the pandemic. I know a lot of old members who disappeared because they returned to work and can't find much time to write their works.
Second, the oversaturation of similar genres and tropes of novels that can be found here. Like, one can literaly skip a few dozen early chapters and still follow through the story.
Third, we have a reputation. This isn't called "SmutHub" for nothing, though smut novels are just a little percentage of the total number of works here. Naturally, some holy peeps avoid this site like a plague, preferring 'clean' sites like Royal Road. /s
Fourth, many readers avoid touching novels with 'few' chapters for fear of getting shorthanded. Investing time and excitement, only to get bamboozled in the end coz the author dropped it.