Not enough time to build those Pyramids in the 7 good years. That doesn’t mean a granary wasn’t shaped in pyramid form with thin walls like a normal granary. Grain bins are still round with a low sloped pointed roof. But the great pyramid has over 2 million stones it. They each weighing from 1 to 50 tons.
The Great Pyramid was apparently built in Moses’ time . The first pyramid, the Step Pyramid, coincides with the time of Joseph. I do not believe the Step Pyramid was built with Stones and could have been erected in a short period of time.
My point is that any Christian belief can be and often is the subject of worldly ridicule.