Use paypal or credit card, also bitcoin could have taken way longer than 20 minutes, sometimes it takes hours too so your example is pretty shitty if you want to make banks look worse than bitcoin. You had several options for instant payment, its your fault for refusing to use them, not the bank.
Because people prefer something that has a faster process. And in this case, Bitcoin is the winner, leaving aside the fluctuations and analysis going forward, of course Bitcoin wins because it is very easily accessible. 1 personal may only be able to access 1 account per 1 Bank, but in bitcoin you have no limits. And especially with an anonymous system which create free people are very happy.