First of all, look here: it's the top of the great Pyramid.
This is another view, where the individual blocks can be distinguished.
As you can see, precision isn't exactly the right word to describe the pyramids.
They were built with the precision one would expect from an organized and educated Bronze Age culture. No more, no less.
There are spaces between the blocks that were filled with sand and rock, and some spaces are large enough to fit an entire arm. The "millimeter" precision of the pyramids is largely a myth. Like a modern contractor, they focused on only a few parts, such as the outer layer of high-quality white limestone from Tura.
Meanwhile, this crack at the top of the pyramid, which is barely visible from the ground, looks like this:
They did their best and it's wonderful, but it's not exceptional precision.