Google says that my phone isn't recording me, and I just have to trust it. People have confirmed this to be true.
I don't see a difference.
I'm not suggesting this is actually happening. I'm pointing out that when you have a single distribution channel for information, users have no choice but to assume the channel hasn't been tampered with.
Of course you could have papers, conferences, and so on proving otherwise. But if they existed, you would only hear of them by word of mouth - which would rely on being in or around a professional network which took an interest in such things.
If Google decided to censor or manipulate the search results about a topic, it could become extremely hard to access reliable uncensored information.
If he hacks the Echo Look, it could blackmail people based on some naked pictures/videos of the victims.
An Echo is an opaque, indivisible blob.
that's not something that can be proven true though.