This becomes less true in places like Germany where lane discipline is very strict. It's not rare to see extreme speed differentials on unlimited speed sections of German Autobahns, but it is rare to see crashes there.
The whole "everything is fine as long as everyone is doing the same speed" bit is a myth.
For every percent increase in speed, this leads to a 2% change in injury accidents, a 3% change in severe injury accidents and a 4% change in fatal accidents.
https://road-safety.transport.ec.europa.eu/eu-road-safety-po...
More about speed vs injury/death rates:
https://www.iihs.org/news/detail/new-crash-tests-show-modest...
https://safety.fhwa.dot.gov/speedmgt/ref_mats/fhwasa1304/Res...
Why? Kinetic energy is a function of velocity squared, influencing injury severity and stopping distances.
Their conclusion is that the speed limit should be increased; there are other reasonable conclusions one might draw, but I would argue against the one that follows from your comment: that nearly every driver on the road deserves punishment.
I would be very interested in if people would then go the reasonable new speed limit or if they would continue in their speeding flocks and only travel even faster. To me it seems like their speed is mostly something they evaluate relative to the rest of the drivers and not to absolute speeds so it'd take quite a change in behavior.
As for [0], the traffic back-up proves only that the vast majority of people on that road are speeding.
My take on it is that when the speed limit doesn't match the 85th percentile speed of actual drivers, something should be changed. Sometimes, (often, in my view) it's the speed limit. Sometimes, it's the design of the road, especially in cases of neighborhood streets that are shaped like highways. Sometimes the answer may be highly-visible traffic cameras, as the advance warning and certainty of punishment will slow down almost every driver.
Driving the limit in the right lane is almost always fine.
But speeding-related fatalities accounted for 30% of traffic fatalities in the US for 2022. Which implies there are plenty of other issues, such that I think saying "speeding is violence" doesn't really do anything to address the problem.
I'd call that extremely dangerous...
Focussing on speeding seems to ignore that there are other serious issues that contribute to the outsized danger on US roads.
[1] https://injuryfacts.nsc.org/motor-vehicle/motor-vehicle-safe...