The question is not does it need cloud, the question is, is it worth it. When you send an audio stream to Google, you are imposing your answer to that question on everybody else in the room.
Or let any third party [view a photo | talk to you on the phone | listen to a voice memo ] with everybody else in the room. We already have answers to those "worth it" questions, largely.
The more important question is whether a third party can use that data to cause you harm, and if that's a concern, I'm afraid the only real solution is to limit your ability to be included in that data.
