The device didn’t improve emissions. It was designed to try and prevent gas fumes from coming out of the tank. It technically did do that… but only if the bike was upright.

there are a billion people in China, and another billion in India.

only 40 mil in California, and most consumer use bikes / cars / whatever are a drop in the carbon bucket.

we could, and should do better, but unless the rest of the world is onboard it's moot.