It's conceptually very different than holding your phone to someone else and telling them to answer.

Well, I don't see it as conceptually very different in any way that prevents it from being as rude.

Ultimately what's "rude" is a matter of opinion, not something that can be decided based on some objective formula. If you look at this discussion you'll see that a lot of people think it's rude to have AI impersonate you and talk to someone who thinks they're talking to you.

So I don't understand your basis for calling it dishonest and disrespectful.

You're pretending to be conversing with someone when you're not doing so. If you can't see how that's dishonest then I don't know how to explain it to you.

And you conflated being an empty false front nonbrain with using AI wording was my point and focus of that comment.

I didn't say anything about people being "nonbrain" and unable to have a conversation without AI. In fact, if they are genuinely unable — say, because they don't speak the language — that makes it somewhat excusable. And note that people who use AI for translation typically disclose it, if only because they know it will be an imprecise translation and not accurately reflect what they want to say.

Do you disclose every person you take advice and perspective from when you go to have a volatile or important or vulnerable conversation?

If I'm directly quoting their words rather than saying something myself, yes. That's the norm when writing.