There were various parts depicting the post apocalyptic world that the movie could've focused on instead of the drive through the desert, for example there was a room where various big women were hooked to milking machines so other humans could use their milk. The scene itself was also extremely realistic imo and I'll give two examples:

-the women were fat and tall => certainly resulted from breeding a line of humans specifically for milking purposes since the other women had a much different constitution;

-most women had a doll to make up for their lost babies that weren't anywhere to be seen;

Also, there were women locked in a room, young and attractive, used for breeding purposes by the tyrant and the resulting babies were often referred to as "property". When the women fled they delivered various messages written on the walls like "humans aren't property" (or something along the lines) and others.

Maybe I'm reading too much into it through the vegan mindset filter but it reminds me much more of industrial farming than it reminds me of human slavery. But you could read it through both lenses I suppose.