He’s going to blow a red light? And you think that’s a better situation than him not blowing it?

Correct.

After the yellow, there is a period of 2-4 seconds where all lights in every direction are red, before cross traffic is given a green. Our 3-second (no camera) driver completes his journey through the intersection during this "red all-ball" stage.

This is a property of the distribution of light timings across a territory,

That is exactly what I said. I went further, and reminded you that traffic light timings are not universal. They differ from jurisdiction to jurisdiction. Generally not by much, occasionally by a lot.

In my country I believe all traffic lights have approximately three seconds.

Your country is the exception, then, and not the rule. Generally, yellow light duration is supposed to be calculated from the greater of the posted speed limit, or actual, observed speeds. 3 seconds is not adequate for an intersection 45mph or greater.

and is still not something to do with red-light cameras.

Where cameras are largely absent, drivers tend to favor "reasonable effort" to comply with the yellow. The "reasonable effort" driver will only brake for a fresh yellow light if they can complete a normal stop; they will not initiate hard, "panic" braking. The additional "red all-ball" signal stage provides ample protection. No additional danger arises from a "reasonable effort" driver choosing to proceed instead of introducing the unnecessary hazards of "panic" braking.

Where cameras are present, drives tend to favor "strict compliance", braking hard and dangerously to ensure they don't cross the stop bar during the red and risk a citation. The "red all-ball" stage is superfluous to this driver.

"Panic" braking introduces a risk of control loss from loss of traction, as well as excess wear and tear on tires, wheels, brakes, suspension and steering components. "Panic braking" poses considerably higher risks than a "reasonable effort" approach to yellow-light compliance.