Earlier quoted context omitted.
That terrifies me
You are not alone. I like the idea that gauges are connected directly to the thing they are measuring. However, I may be disconnected from modern reality in that what might look like a "traditional" gauge might already be connected to the car's computer rather than direct measuring. I'm just not a grease monkey to know the inner workings.
Sensors have redundancies and detections in both sensing and communications so that the receiving end knows when there is an issue and doesn't display false information, resulting in an error code being thrown and displaying a "check engine light".