Technology has been one of the factors that has made things very easy for everyone, gone are days when people were finding it very difficult of sending letters from one person to another do to the lack of internet, so however for a message to be send across it must go through postal office and before it gets to the recipient it takes up to days.
Have you actually made a transaction on chain lately with Bitcoin? Do tell us the experience of grabbing my popcorn and waiting for it!
As for Bitcoin replacing banks, banks offer loans, how could Bitcoin offer you loan when you don't have a penny?
All you can do is go for a thirds part, deposit (lol) a collateral which means you have money in the first place and then pay that guy up, meaning you're still using a 3rd party.
Seriously, we're batting jpg monkeys right now and you talk of killing banks!