Supply and Demand are powerful masters

No insult intended to Max Roster but this is not startling to economists.

A startling fact: Extraction of these resource increased immensely, but prices show no long-run tendency to increase pic.twitter.com/vC60zGXG7K

— Max Roser (@MaxCRoser) August 13, 2016

In fact, that is the basis, in part, to the Simon-Ehrlich Wager which Julian Simon won. From Wikipedia. Citations and notes removed.

Simon challenged Paul R. Ehrlich to a wager in 1980 over the price of metals a decade later; Simon had been challenging environmental scientists to the bet for some time.[citation needed] Ehrlich, John Harte, and John Holdren selected a basket of five metals that they thought would rise in price with increasing scarcity and depletion.[citation needed] Simon won the bet, with all five metals dropping in price.

Supporters of Ehrlich's position suggest that much of this price drop came because of an oil spike driving prices up in 1980 and a recession driving prices down in 1990, pointing out that the price of the basket of metals actually rose from 1950 to 1975.[citation needed] They also suggest that Ehrlich did not consider the prices of these metals to be critical indicators, and that Ehrlich took the bet with great reluctance.[citation needed] On the other hand, Ehrlich selected the metals to be used himself, and at the time of the bet called it an "astonishing offer" that he was accepting "before other greedy people jump in."

The total supply in three of these metals (chromium, copper and nickel) increased during this time. Prices also declined for reasons specific to each of the five:

The price of tin went down because of an increased use of aluminium, a much more abundant, useful and inexpensive material.

Better mining technologies allowed for the discovery of vast nickel lodes, which ended the near monopoly that was enjoyed on the market.

Tungsten fell due to the rise of the use of ceramics in cookware.

The price of chromium fell due to better smelting techniques.

The price of copper began to fall due to the invention of fiber optic cable (which is derived from sand), which serves a number of the functions once reserved only for copper wire.

In all of these cases, better technology allowed for either more efficient use of existing resources, or substitution with a more abundant and less expensive resource, as Simon predicted, until 2011.