I'm not sure you understood what I meant. They are in control of the bot server that joins with the headless chrome client. They can use the CDP protocol to us

I'm not sure you understood what I meant. They are in control of the bot server that joins with the headless chrome client. They can use the CDP protocol to use the screencast API to write the recorded video stream to filesystem/disk, and then they can literally just run ffmpeg on that on-disk-on-server file and stream it somewhere else. But instead they decided to use websockets to send it from that bot client to their own backend API, transmitting the raw pixels as either a raw blob or base64 encoded data, each frame, not encoded anyhow. And that is where the huge waste in bandwidth comes from. (The article hints to this in a lot of places)