That's fair. Although it's partially (mostly?) offset by the preferred solution here of using Uber, which produces tons of extra CO2 from cars idling/driving around waiting for a fare and driving without a passenger to pick you up.

I'm not saying getting rid of these second vehicles is bad, it's great, but Uber's specific focus on rarely-used vehicles only makes sense because they want to make money. Any independent observer concerned about CO2 or pollution or traffic or road safety would want to incentivize getting rid of cars in general, and put more effort towards frequently-used cars.