Why people should use bitcoin, because it is easy to send and receive money from all over the world, no need for iban no need to pay additional fees to the bank so it made our life easier.
People should use bitcoin because it is convenient to use whether you will pay or send money to your loved ones. As long as you have the exact amount that you need to send in your wallet, then you are free to send money anywhere, anytime and whoever the person you want to send some money as long as they also have bitcoin wallet to receive the money you are going to send them.