Gold & silver are not going to be used in any sort of hyperinflation setting, nor is bitcoin--at least not widely. There have been recent examples of hyperinflation in a few countries (over the past few years), and if a country's currency suddenly becomes worthless people will try to get access to and use another stable fiat currency. That makes a hell of a lot more sense to people than using gold/silver, which they might not have and don't have money to buy or bitcoin, which also has to be purchased on an exchange that the typical citizen might not be familiar with (or familiar with bitcoin for that matter) or have the patience to figure out.
Everyone is comfortable with fiat currency. Much fewer people are comfortable using an alternative like bitcoin, which carries an extremely high volatility risk, not to mention network fees that can be costly and the fact that you really have to know how to get it and use it and keep it secure, which might frustrate some folks who are in the midst of an economic crisis.
This topic has been discussed quite a few times over the years, btw.