It's worth pointing out the CrossClimate2 tires are all-seasons and exempt from the requirement. The 4/5 is specific to Consumer Reports all-season category - actual efficiency is going to be noticeably lower than the high efficiency tires they are talking about in the article.

But you're not wrong in general. There are a lot of garbage tires. And that's not even considering the intentionally "bad" tires like the knobby off-road treads that also have the side effect of massively increasing road noise and reducing engine life.

But like a lot of the California rules, they have carved out so many exceptions and have no real enforcement mechanism (the worst offending tires are being imported directly from China). So the reality is that there is not going to be a lot of juice for the squeeze.