Fediverse

The basic idea is that a huge company with infinite money creates software that supports an open standard, such as Threads. Next they spend significant amounts of money driving users to their software, rather than an open software equivalent. Once they've captured a huge percent of all users of the open standard, they abandon the open standard, going with a proprietary one instead. They'll make up some new feature to justify this and sell it as a positive. Because they control almost all of the users at this point, many of the users they don't control will decide to switch over to their software, otherwise the value of the open standard drops significantly overnight for them. What's left is a "dead" open standard that still technically exists but is no longer used. You can find plenty of past examples of this pattern, such as Google and XMPP.