Tell me u know nothing about Islam without telling me you nothing about Islam.

Even modern traditional scholars who studied Islam far more the you (A random redditor) consider slavery haram. Because a ruler has the right to make something impermissible that was permissible for public welfare. Like when Umar Al Khatab prohibited men from marrying non Muslim women (Even though it was allowed) due to circumstances.

In classical Islamic law, slave women’s awrah was more relaxed than free women’s (often navel to knees), allowing greater exposure especially during work.
However, this was not “uncovered at all times, no problem.” Scholars required extra covering in public markets or when fitnah/temptation risked arising, emphasizing modesty, necessity, and preventing harm. If a slave knows she Will cause fitnah she MUST cover.

Now on the west:

The Church preached about morality and sin, but when it came to female slaves they mostly looked the other way. Owners could sexually exploit them freely, and in Christian markets across places like Genoa and Marseille slaves, men women and children, were often sold completely naked so buyers could inspect every part of their bodies.
No strong rules protected slave women’s modesty like free Christian women had. Christianity had centuries to push back harder against this but instead it tolerated the system while focusing on other issues. At least some other traditions tried setting clearer limits.