I think SCTP has everything we need, just more knobs need to be exposed [0]
I have gotten feedback about the performance about Pion's SCTP implementation as well. It is a hard problem. The amount of people who care about SCTP performance + WebRTC and are able to work on it is very small.
If anyone is interested in more about this [1] is a fun issue to read.
libwebrtc is also planning to stop using libwebrtc soon. That would mean all browsers (Chrome, Safari, FireFox) will be on something new. Could be good no idea yet. The ongoing work is here [2]
[0] https://github.com/w3c/webrtc-extensions/issues/71
[1] https://github.com/pion/sctp/issues/62
[2] https://webrtc.googlesource.com/src/+log/refs/heads/master/n...