6 MB/s is trivial for cheap servers and doable for a lot of personal connections (outside US) right now, you shouldn't even wait for Moore's law to catch up.
In 2016 Visa made 86 billion transactions, that is average of ~2600 per second, one magnitude less, than you expected.
In 2016 Visa made 86 billion transactions, that is average of ~2600 per second, one magnitude less, than you expected.