bitcoin certainly has the potential to replace bitcoin and it is a lot better than paypal even. but in my opinion there are two things that are preventing this to happen.
1) is the volatile price: when price of bitcoin is not stable, people aren't seeing bitcoin as a currency. instead they treat it as an investment and nobody uses investment to buy things.
2) the block size: which is making the transactions pile up in the mempool, making things slow and increase the amount of fees by a great deal.
I think that Bitcoin first needs to solve scalability issues, for it to really get somewhere. If Bitcoin aims to become a better way to pay than Visa, Mastercard, or even Paypal, it would needs certain fixes that would help it achieve this goal.
I have no doubt that the more popular, and widely used Bitcoin becomes, the more it will increase in user awareness thus making it a real competitor against Paypal. It all needs faster transaction times, better capacity to handle a hefty sum of transactions, and most of all, price stability. Just sharing my thoughts.
