WN: Idk. I've been to the site...2 or 3 times and have found its staff nonexistent to near outrageously inactive. I've waited an entire month and a few days more for a response to a simple Yes or No question. And they didn't even answer it. They asked me to clarify and then when I did, its been more than a year and I still haven't been answered. Its forums are active depending on the time of day, but I've yet to see actual site staff actively engaging in anything besides a moderator or two that has no real authority to do anything besides ban people. They seem oblivious to anything else since when I last checked, there was a long line of posts from people asking questions that were months old with no responses. Other than that, I have no major opinions.
ScribbleHub: On average, even less skilled and at other times...of similar ability as the average WN writer. They are also the whiniest group of writers I've ever met. Nowhere have I seen more hordes of people crying about 1 stars that they most likely deserved anyway if their writing is to be taken as an example. This place is also consumed with the petty. The number of times I have "offended" a child here over my mentioning of the bullshit hypocrisy of bitching about 1-stars but saying nothing at all about the 5 stars they clearly did not deserve or earn, only to find a shiny new 1 stars on my own stuff despite having no new readers. But of course, I didn't dignify them with my own forum thread spewing metaphorical tears and shrieking about the injustice of it all. Oh and this site has a noticeable, but both amusing and pathetic aversion to RR here.
RoyalRoad: By far the best webnovelist platform I've come across and I have accounts on 9 different sites. Was 13 but 4 of them shut down in the past 3-4 years. Has the best writers on average based on genuine skill and ability. They have higher standards and they expect them. I mean quite a few stories that trend on SH, are frankly horrible...I mean some of the grammar I've read from trending stories here....it's clear they didn't trend on any writing ability or grasp of the English language, but rather because they hit a popular fetish and/or just write general smut which is eaten up on this site regardless of any quality or lack thereof. Its simple. Want to play pretend and "make-nice", not hurt anyone's feelings, and thus never improve? SH is for you. Want to actually improve? Gain semi-professional and more often than you'd think, actual professional advice? Go to RR. Just depends on how thin your skin is and how repulsed you are by actual criticism that isn't just blowing smoke up your arse and feeding your ego.
Fictionpress: The first writing site I ever joined so it's definitely nostalgic for me. The first long-term writing group I ever socialized with that I even migrated numerous Skype channels with and for, until we all ended up on a private discord channel. I've been speaking with the people I met within Fictionpress since 2011 and we still chat very frequently, even the ones that don't write anymore still drop by at least a few minutes a day to say hello. It's still an active site since stories are updated daily, I would just say not as much as SH or anything. And for those crying about the barebones look of the site....and? It's a writing site to post your writing. Not an art show for you to gawk at the pretty colors.
Oh, you said stereotypical? Nevermind. I missed that part of the question.