I never understand the impulse for posters to criticize that which they don't understand. I don't know anything about ISA, as I just heard of it now. But generally speaking, people don't just build and design things for no reason. They don't put those ideas into law for no reason. Our current experience with the evangelicals and their idiotic ideas written into statute perhaps conditions us to think that most legislation is stupid, but I'm extremely confident that a bipartisan group of legislators in Washington State is going to get it right. Or, if not right, not hopelessly wrong.
Anyway, it turns out that ISA is not all that new and it has a track record. It's widely used in Australia. It appears to be mandatory for all commercial vehicles in the EU (post 2022). There have been many studies, it appears (and I'm extremely confident there have been many others not mentioned in the below article), and they tend to show that ISA saves lives.
en.wikipedia.org
Of course there will be instances when ISA inhibits a driver's reactions and perhaps contribute to an accident. If a baseball team had a lineup of all Ted Williams, there might be an occasion when they are facing a Mariano Rivera type and could really use a bunt single and a stolen base or two. But over time, the Ted Williams lineup will prevail.
My guess is that the instances where you need to speed up to avoid an accident are few and far between, and the accidents avoided are generally not deadly. Meanwhile, a large percentage of auto fatalities come from people -- e.g. Henry Riggs from the Raiders -- who are driving wildly over the speed limit. One dude weaving in and out of traffic at 95 can easily cause multiple fatalties.
What's the basis for that guess? Well, the studies seem to show that ISA is life-saving, by a considerable margin. So above is my intuition about why the tech works, but the starting point is the data.