According to Alexa , Wikipedia has actually grown substantially in terms of traffic and viewership, with reach up 12% in the past 3 months. It's inevitable that with several million articles, the number of "missing" encyclopedic ones drops, and thus fewer new articles are created. You can't judge whether something has "peaked" based on fewer accounts being blocked and soforth. Rather than saying it's peaked, it looks more like it's starting to stabilise in terms of quality, while still growing in terms of readership and reach.