Firefox is/was really lacking in WebRTC support for non-P2P use cases - bandwidth estimation support was sub-standard until recently, there is no support for simulcast (multiple video quality encodings) when using H.264, and no E2E encryption support (which is very new to the spec). There has been a lot of back and forth on the Firefox / Jitsi situation but it does seem that most of the time the ball has been sitting in Firefox's court.
