@TNT261
Depends on the commonality of magic. Best not to look at the demon queen for world standard since. You know. Final boss all powerful. A lot of isekais feature the existence of lifestyle convenience magic, but surprisingly, none of them feature like, automated Golems, self checkout systems, or what not to make slaves completely obsolete. Can't think of a single isekai series where magic was so versatile to achieve such a feat.
If anything, I could imagine isekai magic being more unfinancially disabled because magic engines and shit are probably super expensive and cost inefficient in such a technology drought world.
Then there's of course, the liability that humans just don't see slavery as inefficient. World history has slavery littered everywhere, but we ended forbidding it due to the morality, not because of economy. Even if such a convenient thing like magic were to exist, humans are probably gonna cheap out and find a way to be lazy, instead believing a slave using magic for their daily necessities would be easier.
Big plus if they're cute for the bed.