"Slavery was about racism and power and control" is very much not universal. Slavery existed (at varying scales) around the entire world for much of human history for a variety of things. Sometimes, as in US history, there was typically a racial difference between owners and slaves, other times it was a difference of conquered and conquering peoples, and other times it didn't have anything to do with race at all.

Race might be a decent analogue to the difference between human actors and sentient AI, but I suspect work animals (plow horses, etc) would be a better analogy.

Slavery is at least as old as recorded human history, and had nothing to do with racism in most cases (although it often involves xenophobia). The Torah and Old Testament give specific moral guidelines on how to acquire and keep slaves. Prisoners of war are often made into slaves (from earliest times through today's conflicts). You seem to be conflating "slavery" with "18th-century US slavery".

If slavery truly provided no economic advantages, it's hard to explain why countless human civilizations have engaged in it. It's wrong on every moral front, but riches were inarguably built upon its back.

AI is bad for the economy too, but the AI-holders will make a lot of money. There was plenty of racism and control after slavery ended.

True but I would also caveat that it may have been an open economic question back then (I don't know the state of the debate) and the personal-economics of slavery are unmistakable for the "lucky" few.