All smart devices should fail into a safe and functional mode when the smart features inevitably stop working.

I'm horrified that you could possibly advocate for allowing the consumer to have any real control of their own devices. Have you considered the security implications of not requiring devices to be 100% dependent on the manufacturer's server? Users might be able to use the device without first installing the company's app! The user might be able to use the device without the company knowing about it and selling that data for additional profit or using it to train it's AI.