But can’t it be argued that these microtransactions (albeit marginally) decrease the price for those who don’t want certain features while still allowing people who want those features to easily access them?

in all likelihood they’re priced into the total price of the vehicle, so no you’re probably still paying for these features without the ability to actually use them. (and unless you’re getting an itemized bill when you buy a car, how would you even know either way?)