[matrix] excels because its rooms can, depending on the room's administrator, satisfy the above criteria as follows:

1. [matrix] room content is generally primarily text, although posts can include images or video.
2. [matrix] room content is presented chronologically.
3. For each post, the poster is identified. Replies and also private direct messages are supported.
4. Replies identify the poster and optionally the post.
5. [matrix] rooms and room content persist indefinitely.
6. [matrix] room administrators can ban users and hide posts. Any room member can hide all posts of another member.
7. The [matrix] system does not insert ads. When a member posts spam, it's up to the room's administrator to promptly remove it and ban the member.