It would be interesting to see why you think Bitcoin (or other cryptocurrencies) will surpass traditional methods of payment (Cards, Bank transfers, payment gateways etc.).
why does it matter?
bitcoin was never created to "surpass" or replace anything. it is an alternate option that works in an entirely different way (in short decentralized) and the goal has always been to keep it that way not to compete with or replace anything.
Or if you think they have no future please share why.
that is an entirely different discussion which has nothing to do with your main subject. not replacing traditional methods doesn't mean complete failure and no future.
the rest of your arguments regarding 51% attack, speed,... are already discussed in dozens of other topics.