Luke warm take (maybe room temperature): Virtual tech conferences failed because speakers talking at audiences is an entirely bad format. In-person tech conferences succeed *despite* speakers talking at audiences, because the conversations and connection carry it.
…in reply to @pepopowitz
Conference format idea (for someone not traumatized by past conference organizing) -- each session is 10 minutes of a speaker giving a prepared talk, then have someone facilitate the next 30 minutes of unconference format based on the speaker's topic. (does this exist already?)