It died a long time ago. In April of 2019, the creator of Closedverse was searched by the police for possessing child porn, taking the Closedverse server in the process. To this day, Arian has not yet received his devices back. They may be destroyed by now. If there are any updates on this, you will hear it here first.
Before Closedverse, there were various unrelated shutdowns: Cedar shut down due to inactivity, Indigo shut down to protect its staff, and Rverse shut down due to a lack of development (though it has long been back for 3DS users).
After the organized effort to report Arian to the police was a success, the movement went public and started to report and dox as many people who they considered pedophiles as possible, while recruiting the rest of the userbase to join in to help report and harass them. Due to this, it was decided by the owners of the remaining clones that the sites should not be allowed to continue; they seemed to only harbor toxic behavior at that time, and no fix was found for its community issues. After a bit of resistance from Oasis's ownership, it was finally shut down, leaving all the major Miiverse clones to die off. From there, the community slowly dropped off, and moved to Twitter and Discord.
Anyone can make a Miiverse clone. But, nobody has made one with the level of success of Closedverse, and nobody will until the community is there and willing to receive it. Until then, the few users still on smaller Miiverse clone rehosts abuse the lack of moderation to do awful things, and for that reason I wouldn't recommend trying to make your own.
A majority of the people visiting this site are people who were never on Closedverse and are just clicking old links to see what this was.
click here to play kai's bird game