You make some good points but it's all linked to a belief that these devices are on permanent listening mode and recording every conversation in the room. I don't believe they are or do. That's ok, we can disagree on that.
I have genuine questions which the conspiracy theory still hasn't answered. We're told that recording starts when you say the trigger word. This is either true or false. If it's true, which I believe it is, I can go to the appropriate amazon page or ask Alexa directly to delete the recordings. If it's false then there had to be two recording lists per account, the ones you can delete and the rest of the recordings which you (some of you)believe to be everything spoken in the room the device is in. Questions: how do they separate the stuff being recorded into two lots so that they get to keep a secret set of recordings? where are they storing this humongous amount of recordings? Who ( which individuals or organisations,).would be interested in hours and hours and hours worth of unidentifiable mundane conversations?
The Alexa device has to be registered to an Amazon account but it can be gifted so the account holder isn't necessarily the same person who has the device in their home. They really are pretty much unidentifiable unless,, you choose to attach it to an ordering account which needs a delivery address and even then it's not necessarily the address where the Alexa device 'lives'.