Its true that Visa has those advantage over bitcoin which I am not willing to contest but look at it another way that all bitcoin uses to surpass Visa and that is Freedom. In the case of Visa, your funds can be blocked, it can be restricted based on the economy policy of the country you are, it might not be accepted in some countries, you get to save your money with a third party (banks) in other to use the funds, you get traced when you use on some platforms (ask people who want to gamble and its not allowed in their country) among other things. This is the freedom that bitcoin makes available and I would take that over Visa or anything even though other disadvantages might still exist.