Yeah, Royal Road is pretty much what @daeygur said. LitRPG is the biggest genre, and fantasy that's heavy on elements of progression (characters getting stronger) usually do well too, especially if it's something like isekai. Sci-fi is said to be popular there too. I wouldn't exactly agree with that, but it seems to do okay.
Romance, however, is very much not well-liked by most users. If your story has any romance at all, you better tag it as such. Sex isn't liked much either from what I understand, and there's rules about how much of it you can put in your story (I think it's roughly similar to Tapas'.) Any story that involves conflicts between real-world countries, or mentions real-life political figures--basically anything to do with real-world politics--will be banned from the site.
If your story has LGBT+ elements of any kind in it, brace yourself. GL tends to get the least flack there, but I've heard stories of that happening, so it's not 100% safe. BL or having explicitly trans or nonbinary characters tends to bring out negative reactions. The intensity of the reaction depends on how important the character is to the story. I've heard there's a lot less people who freak out about it compared to a few years ago, but it happens. The site itself has some... interesting rationale for having nearly every tag but an LGBT+ one, but I'm not gonna get into that.
Otherwise, I've found Royal Road to have the best UI and visibility. The tags cover a wide range of stories, it's very organized, the search system is good. You're able to schedule chapter uploads in advance like Tapas, plus you can add polls to chapters, there's no weird character limit, you can resize and add alt text to images.
Royal Road has a smaller community, so people are always looking to read something. It's almost kind of a problem, because authors of popular stories are expected to upload daily. Readers are also more likely to give money to authors. You can hook up your Patreon to your story.
Followers are anonymous, which I have mixed feelings about, but it does cut down on Follow-for-Follow type promotions. Speaking of promotions, there's a lot of ways to advertise on the site. You can buy ads if you want.
There's a 5-star rating system that is very important to authors on the site. The more 5-star ratings you get, the more your story's ranking goes up. I still don't know exactly what this does, but I imagine it corresponds with Royal Road's Best Rated section.
Aside from Royal Road and the ones @daeygur mentioned, there's also Wattpad, which is nearly impossible to get visible on unless you're writing something trendy, and FictionPress, which is basically dead.
It is the best web novel site right now if you're looking for any kind of interaction. But depending on what you write, that interaction may not always be positive.
