You can not get materials from the moon or the Mars yet.
If the 自给自足 for teh Earth is not maintained,
someone on the earth will starve. It is as simple
as that.

I don't care about market. What I see is that from
ponit of vire of phsycics, the supplies with tangible physical form must meed the people's physical needs.
If the resources become scanty, soem people will suffer
physically. The issue if who will.