Mastodon metastasized the user store but each site is still a tiny centralized user store. That’s how user stores work. Doesn’t mean they’re automatically monopolistic.

Discord’s taking the Reddit-Apollo approach to forcing them offline — half-assed conversations for months followed by an abrupt fuck-you moment with little recourse — which given Discord’s free of charge growth mechanism, means that — just like Reddit — they’re likely going to shutdown anything by that’s providing a valuable service to a significant fraction of their users, either to Sherlock and charge money for it, or simply to terminate what they view as an obstruction.