We had a number of ways of detecting sockpuppets, and I was part of the mod team at the time, so I could verify they were real users. The change in standards was a combination of things; the old guard, many of whom had left at that point, leaned towards computer literate STEM students who had grown up reading actual novels. In contrast, the new generation of posters was full of ESLs, nontechnical users, and people who grew up reading stories on FFN and RR; the new users were also unfamiliar with forum etiquette and acted like they were on discord. Suddenly, I was having to remind users that English was the official language of the board.

(The phone-vs-computer element also can't be discounted - it's much, much harder to do in-depth long form discussion on a smartphone. Input is a hassle, and doing a bunch of research is extremely annoying when you can't open multiple windows and an editor.)

After 2023 or so, a new problem popped up: posters would read a chapter, hallucinate a series of events that never happened, get mad about what they thought they had read, and then attack the author! Arguments born from a complete lack of reading comprehension were breaking out in all the busiest story threads, with waves of reports every time a new chapter was published. It would not be an exaggeration to say that the average IQ of the board had dropped 20 points.

There was also the monetization aspect to consider; fanfiction used to be by fans, for fans - the work of amateurs, in every sense of the word (amātōrem, 'lover'). While that certainly didn't mean everything was /good/, it at least meant it was a work born of genuine passion. The new authors treated it like a business, churning out updates every week and advertising to readers that they could read several chapters ahead on their patreon. Without even touching the ethics of the matter, you can imagine how the incentives changed the output.