[rektide]

I don't see any technical evidence of that. matrix is a single unified protocol, maintained by a small core contributor group. matrix has no extensibility mechanisms. not sure how you can make a claim like this.

[sdfzug]

https://spec.matrix.org/unstable/#spec-change-proposals

[rektide]

There's a process, guided by core team members, to contributing to the one specification.

This does not sound like extensibility at all. It's monolithic development. Gated by a core team.