[kixelated]

Hey lewq, 40Mbps is an absolutely ridiculous bitrate. For context, Twitch maxes out around 8.5Mb/s for 1440p60. Your encoder was poorly configured, that's it. Also, it sounds like your mostly static content would greatly benefit from VBR; you could get the bitrate down to 1Mb/s or something for screen sharing.

And yeah, the usual approach is to adapt your bitrate to network conditions, but it's also common to modify the frame rate. There's actually no requirement for a fixed frame rate with video codecs. It also you could do the same "encode on demand" approach with a codec like H.264, provided you're okay with it being low FPS on high RTT connections (poor Australians).

Overall, using keyframes only is a very bad idea. It's how the low quality animated GIFs used to work before they were secretly replaced with video files. Video codecs are extremely efficient because of delta encoding.

But I totally agree with ditching WebRTC. WebSockets + WebCodecs is fine provided you have a plan for bufferbloat (ex. adaptive bitrate, ABR, GoP skipping).