[toomuchredbull]

This piece is missing. The audience can't do much. They should at least have chat while people are on stage. Seems like an obvious feature to increase participation.

[janekm]

This is actually something that both Twitch and Youtube can do fairly well. Several science Youtubers put on lectures for school students studying from home, it's a nice format.

Of course that's video... but at least with the YouTube subscription you can listen to the audio without the video.