There is also an opening for someone to market this exact product exactly the same, but just undertake the testing to prove it actually works as advertised to comply with California law.

As a state where air quality is a major public health concern, it seems very reasonable for the regulations to protect consumers from being sold scam products that do not actually filter the air. I understand this concept is well tested and proven, but I think we're all familiar with the general counterfeit product issues on Amazon and I would be 0% surprised to get a fake of even such a simple design.