I'm not really sure how to answer that. I guess it amounts to peer pressure. If you're up against a group that has already decided that these kinds of devices aren't a problem, it's hard to articulate an argument against subjecting yourself to it that they find convincing.
And doesn't this perfectly demonstrate the issue with the "just don't buy one" argument? It's still _possible_ to make choices about your privacy (ex. don't get a smart phone, don't buy a smart speaker, etc.) but it requires progressively more conviction as acceptance of this kind of tech becomes mainstream.