most importantly without vision who cannot make use of a digital cryptocurrency wallet and their only option for a physical transaction is fiat currency that they can touch
Hey, this is a great point for Bitcoin in my opinion!
In my opinion, it should be much easier for a blind person to use a mobile Bitcoin wallet to pay somewhere than to use cash.
They are able to use smartphones very well due to all the 'Accessibility' features (especially on iOS) while paper cash is hard to distinguish just based on feel. Like, what is a 50$ note, and what is a 20$ etc.
As far as I know though, the preferred method for most is to just use a credit card to swipe over the reader. Since there are Bitcoin credit cards, this would work with BTC as well!