If you depend on a third party to handle your IoT device you just own a pricy brick. They can stop at any time, they can change what is supported, they can change the price. It won't change as there is no money in making devices we can run under local control.

https://www.engadget.com/amazon-will-start-charging-for-formerly-free-alexa-guard-smoke-and-security-alerts-184602106.html