The exchange / MM work out the prices based on historical events and their algos. They can't just add an extra 3 points onto IV because otherwise the market will be against the MM when they get placed in a trade as a buyer.
I'm assuming that these 3 points are produced when the VIX is hitting 20-25 or so, you'd have to be the dumbest buyer out there to buy during this period.
Of course they aren't just adding 3 points. The risk premium works out that way. And no, the 3 points doesn't come from when the vix is high. If you read the paper I posted it comes from all levels of the vix.