Market cap is literally price x shares outstanding.
Don't we understand that price is manipulated? Isn't that what this is all about? Dollars obfuscate the true value?
Discussion
It's all relative to purchasing power. You can use silver to measure dollars instead of using dollars to measure silver if you want. I could measure silver in gold or either in bitcoin and avoid the dollar completely.
Perhaps there is a ton of paper silver outstanding or perhaps estimates of the amount of silver in circulation are incorrect.
Neither is inherently a fiat created problem.
At the end of the day if I go to the precious metals store in town I'll pay about $53 to get an oz of silver today. If the merchant accepted ammunition instead I could pay him in that.
These are all just market assets being compared to one another.