Alexas are being used to form a mesh network (Amazon Sidewalk) which was their original intention.

Alexas and Ring cameras for a couple years or so have been equipped with radio transmitters/receivers that are used to communicate with other devices and Alexas/Ring cameras via ISM bands up to a half mile range.

Many devices use these frequencies to do device to device signalling. This means they can communication with your cell phones, Bluetooth BLE and RFID devices, Tile and Air Tag trackers, security and home automation devices, etc and send this info to Amazon HQ via a radio mesh network that you have no control of.

This "feature" supposedly just went live on June 8th of this year. I have a hard time believing these radio transmitters/receivers were not being used this whole time without your knowledge.

https://www.youtube.com/watch?v=ccrUAp4GQvY