How come "Native American" doesn't apply to everyone native to the Americas?

Not all of them are completely like 100% from here because most people are of mixed race like in mexico the majority are mixed of native american and white. Im actually 100% white and im mexican. so yeah not EVERY single person would be totally from there and if you do start saying that then some people could be offended by that. there are people of all races in these places not just one remember latino and hispanic isn't a race.