Actually, for the company like Amazon and Google, they define themselves as companies that do ecology and platform , so their core must not be the hardware Echo smart speaker itself, but must be the voice assistant such as Alexa. Because Alexa stands for new ecology in the Bluetooth speaker line.
Alexa, the voice assistant known as the operation system Android by most of people, but actually it is more suitable for the operation system + supper App. It is also the WiFi speaker then.