I've said on this board before that I have a Tumblr account for fandom. I'm pretty picky about who I'm friends with and most of them are older women, like me, with one or two younger people. The thing we all have in common is the fandom we're in, but the vast majority of us write fic for that fandom too.
What I've found is the younger people in the fandom are all excessively woke - there is a lot of 'I would die for trans/non-binary/ace/aro/etc' stuff and many of them will say that they're gay or bi or non-binary or trans or something. It's rare to come across anyone in that fandom under the age of 20 who isn't 'different' in some way.
How this manifests itself in fic is interesting - one of my friends writes prolifically (she's also a published author) and her writing is well-followed and loved. She writes m/m (the biggest pairing in the fandom) and is sexually explicit in her writing. The interesting part is that younger fans will often target her with pretty strong hate for pairing these two men together and call her disgusting for suggesting it - while at the same time claiming to be all about gay rights.
The younger fans that write, in my experience, also tend to be the most extreme in what they write. That's where we tend to get rape, incest, extreme BDSM and death. And there's a correlation between the young women writing this, and their personal lives (if they're telling the truth). An awful lot of broken relationships with parents and an awful lot more worrying relationships with partners. I don't know how much of it is for shock value but I find I cant read a lot of the fic by these younger members.
I read one or two ABO and they weren't for me - I really didn't like the power dynamics in them. MPreg make me feel ill so I don't read those. And I definitely avoid anything with non-con or incest. I think, as an older member of fandom, I am conscious of checking tags extremely carefully when looking for something to read and adding plenty of tags of my own when uploading something I've written.
The majority of my own writing focuses on m/f though and yes, I write explicit sex, but it's very vanilla - the worst I wrote about was someone having their hands tied behind their back in role play and consent was implicitly sought beforehand. And it was one of the things my friends picked up on - 'I loved that he checked with her first'.
Someone pointed out on the other thread that kids are learning about sexuality through fanfic and I take issue with that. I know of at least one fan who has been told by their parents that they should not have a Tumblr account but have been given an ipad by school and use it secretly that way. There are others on Twitter who I'm sure have parents that are completely unaware of what their children are up to - I don't interact with minors but we often have mutual friends so I see what they post, and it ain't pretty.
But the issue I have is that we, as adults, use A03 (or whatever) carefully and correctly - we tag extensively, we share between small groups of friends. We are not responsible for other people's children who are not being monitored by their parents as to what they're doing online, and I feel like laying the blame at the feet of fanfic writers is just another way of censoring women online.
Sorry for the essay!