Bitcoin lacks a real world use case that cannot be realized by existing payment networks. There is no instance where Bitcoin is easier and more convenient to use than traditional remittance networks or fiat. Simply put, the world does not NEED bitcoin. The best we can hope for is a collapse of the world bank but until then credit cards and banking instruments remain easier safer and more convenient
It might not be easier and more convenient at the moment but it should be in the future. Why pay $50 dollars or some other extortionate fee to send money around the world when you can do it for little with bitcoin. You're also forgetting that some people in developing nations don't even have access or are allowed a bank account which bitcoin will solve.
I agree. World doesn't need Bitcoin for buying a cup of coffee or for buying anything that can be bought with the credit cards maybe, but for remittances world needs Bitcoin badly. For sending quickly and much cheaper money half the way around the world, the word needs us for this as well. I gave you just two good, strong use cases.
So why adoption takes this long?
1. Bitcoin is still overly complicated, yes it is. To buy and secure your coins, you have to be very, very computer literate which most people are not.
2. People tend to change their habits very hard, especially financial habits. So this will take time, especially when we are dealing with money. People need to trust it first.
3. Directly or indirectly sabotage by our opponents. Yes, if banks came tomorrow and said to their customers, use Bitcoin, it will make our and your life much easier, of course they would boost our adoption almost instantly. Will banks ever do this openly? I don't think so. Instead they see us as a competition and they are building their own blockchains.