California is famous for having different emission regulations. They have an exemption from the national law that they're allowed to make stricter emissions and gas mileage regulations. None of those should prove to be a burden for anyone who wants to sell a battery EV in California, because there's no standard that applies only in California to EVs.

Imagine you owned a store, what seems better, having 40 customers come in and all of them buy or having 80 people come in and all use up time with a salesman and then only 45 people purchase. You would end up spending a much more significant amount of the sales revenue on the larger showroom and more staff. This isn’t my opinion this is why the American market has been prioritized, that and the fact that Americans spend more on cars per year

California has different emissions requirements (not safety) but since they are a strict upgrade to the rest of the US (and comparable to other int markets) as long as you follow their requirements all cars in the US can be sold without any contradictory requirements

A very common kpi used is to examine the success of a campaign in a per target demographic so having the much lower response rate is worse