I think we broadly agree, but there seem to be important nuances that you're missing. As a slave back then, it actually wasn't as simple as saying "not being owned is better than being owned."

We see it that way because there are other things that we take for granted. Like that there would be opportunities for us to make our own way and provide for ourselves. But that wasn't the case for many black people back then. Most had no education, no marketable skills, nobody was willing to give them work. After emancipation, many slaves simply starved to death. Some wanted to remain slaves because at least they had food and shelter.

The idea that not being owned is better than being owned is itself a marker of how conditions have improved. But it's important to understand the context of people's lives at the time they were dealing with these questions. Judging their circumstances purely from our perspective today, pretty much guarantees that we'll miss important details.