That's not a particulary strong argument... The amount of magnesium in the human body is .1% by weight. That's not too far different from the amount of rare-ea

That's not a particulary strong argument... The amount of magnesium in the human body is .1% by weight. That's not too far different from the amount of rare-earths in an EV. In the case of a human, i would not wish magnesium deficiency on them, it is not fun, can have severe long-term consequences (such as death), and generally is something that medical professionals will find concerning. In the case of an EV I don't know what the consequences of removing rare-earths would be, but the fact that it's a tiny percentage of total mass doesn't imply that they can just be dismissed.