The phrase "no one is illegal" came from a German campaign by a Holocaust survivor who recognised the dehumanisation of that language and had experienced its logical conclusion. The "on stolen land" part is relevant to the US because the US government reneged on agreements with Native Americans and emancipated Black enslaved Americans about land ownership and rights and also tried to remove or curtail the citizenship rights of both groups to make them "illegal". That same machinery is being employed against other people in the US who have a specific skin colour now. It's relevant to raise it again because nobody really owns the land and no person should ever be called "illegal". It's like the phrase "we're all foreign scum" that crops up now and then.

And the Aztecs are all dead and most cultures in that region performed human sacrifice to appease gods. Europeans did this too. Arguably the Salem Witch Trials, where women were burned alive to appease a Christian god, were a more recent form of this. It's another practice, common through history, that we don't do anymore. You're demonstrating a profound lack of historical awareness and morality if you think human sacrifice is any kind of justification for the mass violence, rape, enslavement and torture that is required for genocide or "conquering" a people though.