All my life, libertarians have predicted massive price inflation (hyperinflation) and the collapse of the dollar. After 40 years of these predictions I've become numb to them.

Eventually fiat money will go to zero. But to misquote someone: the dollar can remain valuable longer than you can remain solvent. The "cheating" of printing fiat money, especially as a reserve currency, is supported by foreigners that already hold massive amounts of US treasuries and don't want to see their investments collapse, and so they continue creating demand for dollars. Recent news of BRICS finding alternatives will put a shock through the system, but markets are not predicting this shock to be both imminent and severe, and it doesn't make sense that Saudi Arabia (for example) would totally abandon the dollar as that would tank their treasuries. The move out of the dollar will be gradual.

Also, price inflation is strongly influenced by the velocity of money. As they say "you cannot push on a string" and if nobody is spending their massive wads of money, prices won't go up. You are right to be aware of the fact that there are massive wads of money and if-and-when this is eventually spent it will push the dollar down, and you are right that printing money is not fair, but it remains very hard to predict when these massive wads of money will circulate. So the dollar is very risky - it could fall, it could fall rapidly, or it could go up in times of uncertainty.

Bitcoin is more sound as it's supply will only deflate and thus it's value will always trend upwards over time, so long as it remains legal (or accessible nonetheless). Volatility in bitcoin is generally a short-term transient phenomenon reflecting market conditions which are cyclical and unpredictable.

Anyhow, that is how I see it. I am not an economist.