Plus, devices like that are almost guaranteed to become garbage very rapidly when the vendor decides to stop operating that central command server, wherever it is. And unless you're paying a maintenance fee, they're going to cut that off pretty quickly once they stop selling new units of that particular model.

It's the biggest reason why I'm skeptical about all things IoT: too much "cloud" without an SLA or any guarantee of longevity on the service side.

Not if you keep IoT devices on a separate network