[choeger]

That's obviously wrong. If one resource gets scarce but retains its use, it will get more expensive compared to other resources that remain plentiful.

All commodities together feed into inflation. So either some will become less expensive or some will outpace inflation.

What we're seeing here is that resource extraction can get better, so resources aren't really scarce. But there are certainly some commodities, not reflected here, that became much cheaper. E.g., corn or meat, so these metals might have become more expensive in relative terms.