Who's proposing such a device to get widespread adoption? I've heard of sensor data signing [1] but not what you're describing.
The key idea is to leverage the array of sensors built into modern smartphones and tablets - accelerometer, gyroscope, GPS, WiFi/cellular signal data, etc. - to cryptographically sign the sensor readings along with the visual data itself at the time of capture. This extra layer of verifiable sensor data would help establish that a recording originated from a real physical device in a particular place and time, as opposed to a purely digital fabrication.
Historically, technologies like digital signatures and public key cryptography started out in niche military/government applications before becoming ubiquitous in the computer era. In a similar way, sensor-level authentication of audiovisual media could follow an adoption curve driven by the growing need to combat sophisticated AI forgeries.