Sure I get that, I run into that a bit also when talking about how kids are basically a modern day slave class legally speaking in the US. I think that’s probably because slave can mean 2 things, 1 being an umbrella term for “worker with freedoms removed and who is not earning capital or power,” and 1 being a specific term for US antebellum slavery which looked quite different from other forms of slavery.

The second use of the term is why people are being really pedantic imo. Because a lot of minimizing has been done to say that black slaves back then didn’t have it so bad, or that they had the same deal as the Irish who were indentured servants. It’s a really common white supremacist talking point in the south that typically leads to their point that black people are actually inferior because every race has dealt with slavery but they are behind because they suck etc. Typical racist garbage, because they want black people to be slaves again and are openly advocating for it with their rhetoric.

So yes ‘slave’ has a charged meaning. Similar to how pitbull can mean “short-haired medium to large sized terriers including staffordshires, bullys, dogs argentinos, American pitbull terriers,” or pitbull can just mean American Pitbull Terrier.