Thank God I dont use alexa or any other “smrtcrap” devices. That doesn't mean alexa or any other "smrtcrap" devices aren't using you.
Every computer or smartphone you own is listening to you 24/7.
The only way to avoid it is to own none.
Did you know that there are test instruments that can monitor packets from cellular phones? Did you know that when cell phones are exchanging audio with the tower that there are two fully laden packets every 20 milliseconds? Did you know that when not conversing that there is only one short ping packet every five seconds?
How do those ping packets carry enough data to represent audio?