It appears the lemmynsfw is gone.
There were only two people involved with the server, and only one of them had the keys and even the most basic information about the hosting. That person has been MIA since October.
Given that only a single person had any access and knowledge of the infrastructure means that this was inevitable.
Lemmy is still here yes? You're commenting on a Lemmy post and reaching other Lemmy users. That is what decentralisation solves. If it was centralized this would mean the end for Lemmy.
Decentralization does not solve the issues of this specific server going down and making many contents inaccessible.