I hadn't heard of this. I just spent the last hour setting up my own federated server and playing with some clients. This is pretty great! A lot like Slack in terms of UX, but without the corporate walled garden.
To answer that question for yourself just requires reflecting on the benefits of open source vs. proprietary software.
Also, in this particular case, Matrix also appears to be a well thought out platform for decentralised communication, one that is likely to be flexible enough to meet the needs of multiple different forms of communication.