Regardless of inflation in the USA, the paper american hundred dollar bill has a life of its own- it is the currency of choice, in many parts of the world, where local currencies are questionable, where banks are not to be trusted. over 2/3 of the actual paper bills are not even in the USA, and are used for all sorts of transactions, legal or not, by people who dont know the Federal Reserve bank from a hole in the ground, who care naught about US debt levels, and, for many, dont even read.
Drug deals in the golden triangle, asset smuggling from Moscow to Cyprus, passage from Turkey to Greece by rubber boat, Cocaine deals in Columbia, car sales in the persian gulf, even house sales in Buenos Aires- the Benjamin has a life of its own, which is reflected by the blue rate, completely independent of what economists or doom predictors say about the US economy, and, for the foreseeable future, it will.
A hundred bucks has spending power. Its disconnected to reality, and has been for decades.