Ok assuming Central African Republic has a low internet usage rate, what guarantee is there that people will start using some new physical form of Bitcoin is not a trustless system like what the electronic form of Bitcoin?
Since they don't have internet, they are left with two legal tender options: a fiat currency with a history and high probability of continued debasement, or a bitcoin note which is programmatically immune from debasement. Having had experience with fiat, the bitcoin note is more attractive. While bitcoin is currently volatile, a wider use of bitcoin will gradually stabilize it. Its value is also likely to continue increasing as it becomes more widespread internationally and halvings further cap the supply of bitcoin. It's our job to make BitCheques as trustless as possible.