That depends on your definition of decentralization. Because of the way most people set up their apps, almost all Matrix users and ~all Signal users are using a centralized app under this definition.
> That depends on your definition of decentralization.
Decentralization literally means "not centralized". If you have a single centralized entity serving all your messages through a set of centralized servers, it makes the setup what?
> Because of the way most people set up their apps, almost all Matrix users and ~all Signal users are using a centralized app under this definition.
Yes, they do, and it's centralized. What exactly makes you think otherwise?
it being encrypted but routed through a single companies servers means its just as centralized as if it were unencrypted though