Any device that you buy which requires an app to use is not actually owned by you. What you have purchased is a license to use the product, a deal which the cloud owner can alter at any time. Your data goes through the internet into the company's cloud before being sent back through the internet to your device, this allows companies to monitor how often you use a device, for how long you use the device, and potentially what you are telling the device to do. If you want to own your smart device, you have de-sync them from the cloud and connect them to a central smart hub in your own home (either a PC set up for this purpose or a raspberry pi designed for this). Make it so these devices can only talk to an offline hub and work for you and not for the companies who want to spy on you.