The medieval cathedrals of Europe are known to have been built without slave labor because slavery wasn't practiced in Europe at that time, but they were built by serfs, which is not totally dissimilar. It's hard to describe past labor relationships with modern language since they had very different societies.
Agreed, and we really don't know / have any good information on how the locals felt about things then.
I imagine being common citizen back then is terrible, if only relative to my experience, but on the other hand they may have been enthusiastic to contention to an important religious activity. Really hard to know their circumstances / point of view.
