Yes, it's more complicated than I have painted it. There was stratification, kings and slave and all in between. But there was no wage labor. You are either paid for the product or you're enslaved but you're not temporarily unemployed or lose your job. You don't lose your job to automation, your just done earlier

My understanding is that the "built by slaves" theory is a bit outdated. The pharaoh had access to a massive population and outside of harvest stations could be engaged in construction efforts. Slaves were very likely part of it too but not the majority of the workforce