I can’t tell if this is going to replace Visa/Mastercard or be offered in addition to Visa/Mastercard to handle transactions for locals while still allowing transactions to be viable for everyone else who might be passing through.
All stores accept this as well as VISA/Mastercard since they want to maximize who they can get money for, so it's already a common place practice for payment terminals to do this. Tourism alone is enough of a reason you would accept VISA/Mastercard still.
Yes, it will for most nation wide chains, touristic places, and anywhere that has comfortable margins.
For smaller shops and tighter business models, dropping the costlier networks will be the first thing they do. Same way a decent number of shops won't accept Amex, or just no card at all.
Now if we're is cheap and popular enough, there might be more stores getting rid of cash as a reaction.
You'll live life as if you had AMEX instead.