Egypt didn’t use slaves to build the pyramids. They used paid skilled workers. We have their living areas and pay receipts. You are working with outdated information. Cathedrals cover a 1700 year period and multiple labor strategies. I’m sure some were built with slaves but the majority weren’t and slavery was all but absent for the majority of the period unless you count serfdom, but serfs didn’t have the skills to build them so they don’t count.