Helium isn't a good example. Prices were artificially low for a long time due to the US federal government gradually selling off their strategic reserve. As a scuba diver it was great but we knew it couldn't last.

That wouldn’t explain the 8% growth per year from before the sell off of the government strategic reserve which should have provided downward pressure. In fact, the supply chain shocks started happening just as the reserves got depleted. Shocker that.