Wheras presumably amazon or pure internet search history does not provide exactly the same function?

I mean yeah, audio does provide a new attack vector, but then pretty much every new technology does.

There is a difference between deliberately typing those sorts of queries into a search field on a website, and a remotely-administered audio bug capturing every random bit of conversation within earshot.

a website quite literally is a remotely administered user input gatherer. I understand the concern about open microphones, but we've had this conversation about everything from laptop microphones to smart TVs before. I don't see how something like a new device changes the equation much compared to those things.

You and I and many others on internet forums may have had that conversation, but most non-geeks in my social circles haven't. Deliberately fucking with their voice assistants is a great way to quickly get them thinking hard about the issue with a minimum of conversation. It's past time to appeal to logic. It's now time to go straight for the emotional jugular by inducing some panic.

... followed up by "And now that search is tied to you! Have fun in prison!"

This could be a source of plausible deniability.

"I didn't search for that. My friend said it as a joke!"