It’s “let’s believe that google and apple wouldn’t let this data be misused."

This is only valid for your specific voice commands. They're of course transmitted to and processed on their servers. That's something they could misuse, yes, but that's not what the article is about. The article is about whether your phone always listens to you, and there's no proof of it. People are repeating this claim all the time, but no one has come up with a proof. If you think about it also doesn't make any sense at all. This would cause so much data usage, people would have definitely noticed that at some point. The storage and processing requirements on Googles / Amazons part would also be ridiculous. But no matter how you look at it, it's up to someone who makes a claim to prove that it's true, that called the burden of proof and no one has managed to come up with a proof so far.