Of course those who worked on it were fed and housed for the 20 years of construction. But it was a hierarchical society, effectively, yes of course they were slaves. There's a modern political imperative that has nothing to do with anything but nationalist politics in Egypt and an ass-kissing need for those who want to work in Egypt. No need to buy into the fiction.
Weren’t Egyptian workers on the pyramids just “paying their taxes” by working. As I understand it was “corvee labor” work as a way of paying taxes & performing religious obligations.
https://en.wikipedia.org/wiki/Corv%C3%A9e
Also technically didn’t the Pharoah & priests own everything? So everyone was a slave in a sense except those top dogs. Not at all comparable to what is popularly understood as slavery.