There are Windows machines for high end and low end, but macOS machines only for high end. Low end includes all your grandmas, unused workstations, and people apathetic about computers because they don't use them much. All your laptops kept folded under dorm beds and used only for assignments.

The same effect shows up to a greater degree on mobile, where Android has something like three times iOS’s units sold yet the same amount of mobile traffic and half as much app store revenue.