How exactly does E2E encryption work for something bandwidth intensive like Zoom? It can't possibly be encrypting the stream with a different key for every part

How exactly does E2E encryption work for something bandwidth intensive like Zoom? It can't possibly be encrypting the stream with a different key for every participant, the bandwidth requirements would be impossible. Is a new key generated for each stream, which is then individually encrypted with every other participants public key, and then sent to the participants for them to decrypt?