Is it like that because it's true?

there definitely is such a curve. I just can't imagine its optimum is at 5+ seconds between cars, at least at the highway speeds we drive in dense/often congested areas (~60mph / 100kph where I live). Intuitively I'd put it around 3 seconds.

I agree there. There's a lot an individual can do to dampen the compression waves if they leave 3 seconds instead of 2. I was being facetious with 5 seconds, but in some situations the 3 second distance is still not enough time to react. For example, when there is a stationary obstruction and the car in front obscuring it swerves instead of braking.

Additionally, there's a lot to be said about vehicles not acting like they have human drivers. This Tesla basically acted like a psychopath.

I have one car with regular cruise control and one with adaptive cruise. I am more relaxed with the standard one because I get the signals I need visually to know if I need to pass the car in front or not. I can't tell if my other car is going to drop from 80mph to 60mph all of a sudden until it's basically happened. Better autopilot could help, but then would I end up in this situation?