Is this their first platform death? Come on, Wired!
Millennials have been losing platforms on the Internet for pretty much the whole history of the Internet. Just a handful of "social media" type services that have risen and fallen in my years of the internet: AOL Instant Message, ICQ, IRC, Usenet, LiveJournal, MySpace, on and on.
Most of these aren't even properly "dead", many I just.mentioned still have big user groups too. They just lost a critical user share when folks moved on.