Fediverse

Federated platforms don't die to corporate-type enshittification. They die to spam or elitism.

If operators fail to collaborate on keeping spam down, the platform becomes unusable or greatly-diminished due to spam. See Usenet for example — yes, it's still around, but it's greatly diminished from the 1990s. New projects and organizations don't tell participants to subscribe to a Usenet newsgroup for discussion. (Curiously, email mailing-lists have outlived Usenet in this way, at least for technical projects. While email is federated, any given mailing-list is centralized.)

If the technology isn't developed with an eye to new users' needs and new use cases, because it's "good enough" for the existing established users, the platform becomes dated and gets replaced by something trendy and corporate. This is IRC vs. Discord and Slack. IRC has a higher barrier to entry and infamously doesn't work well on mobile — but it's good enough for the old farts who care about it, while the young farts move to Discord instead.