If you are seriously comparing Visa network to protocol like Bitcoin, it is you who doesn't understand economics and scalability.
Visa network is centralized and owned a company. Bitcoin is a protocol with no central ownership. Additionally, visa network is currency-agnostic and enables payments in any currency they want to support. Centralized services like Visa can work with Bitcoin in various ways, for example the settlement transactions can be done with Bitcoin.
Additionally Bitcoin has been developed from the start with various centralized services built around it - without those services it wouldn't be popular at all. Any centralized service can scale as well as Visa. Though where Bitcoin provides value is not near retail payments, and while there have been bitcoin-reloadable visa cards I think that is not very interesting use-case.
Visa network is centralized and owned a company. Bitcoin is a protocol with no central ownership. Additionally, visa network is currency-agnostic and enables payments in any currency they want to support. Centralized services like Visa can work with Bitcoin in various ways, for example the settlement transactions can be done with Bitcoin.
Additionally Bitcoin has been developed from the start with various centralized services built around it - without those services it wouldn't be popular at all. Any centralized service can scale as well as Visa. Though where Bitcoin provides value is not near retail payments, and while there have been bitcoin-reloadable visa cards I think that is not very interesting use-case.