The ring is an always-on camera. My phone is not that. My phone may leak some information about me, and its basic job (cell phone) provides a record of location data, but that's not the same thing as forcibly making a home security device into part of a police state panopticon.
Are you sure your phone microphone isn't always on? At the very least your voice assistant is listening all the time to detect the trigger word (does this send the voice to the cloud for AI assisted detection?). Also if you search for articles about Ultrasonic Beacons, they imply adware tech is listening all the time too.
My smart phone is not recording video all the time and uploading it to somebody else's computer. It does send location pings to the cell tower when turned on... However, I can easily turn my smart phone off, or leave it home or somewhere else. Security cameras and thermostats and refrigerators aren't so easy to just turn off.
There are billions of smart phones out there, and hundreds of thousands of technical minds both working at the companies who make them, and owning and checking them for these things.
Please provide a singular credible source for your statement.