I think cryptocurrency will be an alternate payment option but not very soon.
If you will analyze the happenings today, crypto's are already being used as a payment.
yes you are right, in some countries crypto can already be used for payment. however, the volume of use is still low, because many people prefer to use mainstream payments. for now it might not be big enough, but in a few years I'm sure this will be good.
The volume is low because people are still skeptic about it to use as payment.
I'm very optimistic that in the future, there will be more bitcoin transactions that will be accepted. That banner of 'bitcoin accepted here' will be everywhere.