Remember that Visa transactions are not equal to Bitcoin/Ethereum transactions. A visa transaction is just a promise of payment at some future date, probably. That's why they can have such a high rate. Bitcoin and Ethereum transactions are settled cash in your wallet. Apples and oranges.

Bitcoin has the lightning network based on Bitcoin smart contracts that can do Visa-like rates of Visa-like transactions. I don't know if Ethereum has anything like that.