To put a finer point on that “outside of Sparta” note:
In Sparta, we’re talking about 15-20% free folk depending on the point in time. Even other Greek cities looked at Sparta and its 85% population of Helots and go “Okay, that’s a bit extreme, don’t you think?” Plutarch, himself belonging to the (non-Spartanian) Greek elite, at some point remarks that “in Sparta the free man is more free than anywhere else in the world, and the slave more a slave”.
Slavery was never rosy, but Sparta made a contest out of who could treat them worst.
To put a finer point on that “outside of Sparta” note:
In Sparta, we’re talking about 15-20% free folk depending on the point in time. Even other Greek cities looked at Sparta and its 85% population of Helots and go “Okay, that’s a bit extreme, don’t you think?” Plutarch, himself belonging to the (non-Spartanian) Greek elite, at some point remarks that “in Sparta the free man is more free than anywhere else in the world, and the slave more a slave”.
Slavery was never rosy, but Sparta made a contest out of who could treat them worst.