The voice assistant space is dying: https://arstechnica.com/gadgets/2022/11/amazon-alexa-is-a-co... Some of the comments below are part of the explanation why. It doesn't work as well as people were hoping, and it's a solution in search of a problem with limited application and it seems little monetization. The above article sums it up better from the big tech company's perspective.
The "voice assistant space" also includes Siri, Google Assistant, and Cortana, so it's not going anywhere. I'd contend that it's absolutely not a solution in search of a problem; it's much more of an unsolved problem, and a big part of the "why" is - voice recognition/assistance tech still maturing - major players are insisting that the tech supports their walled gardens - price points are still a problem The last tw…
For what it's worth, Google Assistant does have an open API to create new devices. It's not open source, but you can certainly experiment with your own custom form factors. There's even a tutorial:
https://medium.com/google-cloud/how-to-build-your-own-smart-...