Comment by Arathorn

Matrix has a pretty comprehensive featureset with clients across a broad range of platforms.

The accusations of it being overengineered come typically due to the Synapse server implementation being slow. This is basically an artefact of Matrix being quite complicated to provide a byzantine fault tolerant decentralised equivalent to WhatsApp or Slack etc - and time has gone into fixing stability and usability rather than performance. Meanwhile performance is getting better, but progress is slow due to tragedy-of-the-commons related funding challenges. We will get there in the end, though.