Moxie's argument can be found in its essay "the ecosystem is moving"[1], which is highly fallacious. Moxie's Signal is about control and building for himself the same kind of monopoly as others currently enjoy. You can find evidence of that through the libresignal issue tracker on GitHub where he rationalizes barring access to 3rd party clients or servers[2].

He sees federation as the technically superior approach (and as beneficial for privacy and security), but also as a threat to himself, which makes the point that he doesn't have your best interests at heart.

[1]: https://gultsch.de/objection.html

[2]: https://github.com/LibreSignal/LibreSignal/issues/37#issueco...