This blog post happens to use Echos to play the music. That's not the interesting part, though. Home Assistant and Node-RED are the cool bits, and they're completely local network services; no wiretapping required.
I've done a lot of automation using HA and Zigbee and Tasmota devices, and it's been awesome. I have no cloud I rely on for anything. When my Internet service goes down seemingly every night at 12:30am, I'm glad I can still control lights, alarms, etc.
You can also use a slightly modified version of these sub flows to mute all Alexas of which I do. I try to do everything local behind a firewall. There is just somethings like Spotify / speakers / mic that is really hard to do / very few products that work local only.
I've done a lot of automation using HA and Zigbee and Tasmota devices, and it's been awesome. I have no cloud I rely on for anything. When my Internet service goes down seemingly every night at 12:30am, I'm glad I can still control lights, alarms, etc.