>Bitcoin will eventually become not less volatile, but involatile. This is because you won't be measuring its value in USD, but you will be measuring the value of USD in Bitcoins.
Accepting a hypothetical future where other currencies are generally compared against bitcoins, bitcoins would still not be "involatile." While markets tend to use one currency as a reference point for another, there are other reference points available. Economists often use a basket of staple goods, like milk and eggs, to get a sense of how much the dollar has fluctuated in value. As you're aware Bitcoin was designed to be deflationary. If we expect human population to rise, and bitcoins to be stagnant in number while remaining a cornerstone of the economy, our hypothetical future should see the value of bitcoins continuing to grow in the long term.
Accepting a hypothetical future where other currencies are generally compared against bitcoins, bitcoins would still not be "involatile." While markets tend to use one currency as a reference point for another, there are other reference points available. Economists often use a basket of staple goods, like milk and eggs, to get a sense of how much the dollar has fluctuated in value. As you're aware Bitcoin was designed to be deflationary. If we expect human population to rise, and bitcoins to be stagnant in number while remaining a cornerstone of the economy, our hypothetical future should see the value of bitcoins continuing to grow in the long term.