If you steal something from me, you infringe on my possibility to use my property as I wish. If you steal my car, I can no longer use it. If you steal my intellectual property, for example the song I created, I can no longer make money with that song as I did before.
Most examples of "cultural theft" are just examples of cultural transfer, one culture adopts ideas or practices some other people invented. Did the Maori invent tattoos? Or maybe did their ancestors adopt it from some neighbor tribe long ago? - - When we in the West adopt tattoos or a music style Black people created, the possibility of those who used it before is not infringed. The Maori can still practice their tradition like they did. Black people could still play the Blues like they did, even after white musicians started to adopt this kind of music.
The whole concept that a culture "owns" some idea is rubbish. Do we Germans "own" our words? Did Americans, when they adopted German words like "kindergarten" or "zeitgeist" steal our property? Does not make sense to me.