I hate to be the bearer of bad news, but humanity has not abolished slavery. Most recent stats estimate ~28 million people worldwide in the forced labour category that most would mentally associate with the term. That rises to nearly 50 million going by the modern definition that includes forced marriage, child rearing, and subservience without recourse.

Yes, in 2025.

Sadly the United States abolishing slavery for ~4 million within its own borders in the 1860s did not represent humanity as a whole.

On paper the problem is solved because it’s illegal to openly buy and sell another person. In practice the exact same treatment and de facto ownership and exploitation of other people remain without any meaningful enforcement in many parts of the world.