As an example, if you want to transfer £200 to euros for a holiday, you will have around an extra €30 spending money on your holiday by using TranserWise than you would if you use a bank. Banks = unethical fees. TransferWise = more money for you.
And from the horse’s mouth: “Banks charge hidden fees when you send money abroad. With Wise you save up to 90%. Problem solved, money saved.”