?

1. I install synapse (a matrix server) on my own machine. I install Element on my own phone. I connect one to another, and via the server to other servers.

2. I install a client that connects to reddit. Same reddit as everyone else. Same reddit as the reddit website.

There is a rather significant difference, isn't there?

EDIT addressing the 'hate speech' part, you are correct. If one reddit client is banned, all should be banned. But that is not true for communication apps, like Element.