There is over a cubic km of earths crust that can be mined per person on the planet using current technology. There is zero need for space mining as actually rare materials we care about like Oil don't exist in space.
The problem with the Earth's crust is all the stuff on top of it. We can't extract 100% of the earth's crust's value, or anywhere near it, without disrupting huge swaths of wild and human habitats. We're already causing a mass extinction at our current rate of consumption, do you really want to increase that?
We need to move away from oil so that we don't kill ourselves with climate change regardless.
We can keep the top ~5 meters of earth and extract what's beneath it without disrupting ecosystems. However, the current approach of massive mines is cheaper and frankly we have such a vast abundance of resources that's working fine it's not like every person on the planet has any need for 20+ lb of gold. Further, we can always just mine old garbage dumps as elements are not destroyed just shifting chemical bonds.
But this very article is talking about the possibility of running out. Do you disagree with the premise of the article? Nature is a respected publication, if you think they're wrong you should work on a properly sourced and peer reviewed rebuttal.
If you read the article they are not saying that's how much of this element is in the crust. They are making an economic argument which is a secondary issue. Note: People are not making economic arguments in support of space mining just an abundance argument.
An economic argument for space works too. The profits of space mining outweigh the costs by several orders of magnitude and the abundance of resources far outstrips what's economically accessible on Earth, and as a bonus doesn't ruin the only place in the universe we know can support life.
Also, having a bore hole at a certain depth doesn't mean we can extract material from that depth in useful quantities.
I think your vastly overestimating the costs of mining stuff on earth and underestimating the costs of mining stuff in space.
On top of that if you bring back say a cubic mile of gold then gold is not going to be worth nearly as much. Which prevents scaling up space mining as we simply don't need that many raw materials to pay for multi trillion dollar space mining enterprises to bring costs down.
