1) The Yemen number is for the whole system. The energy to send one transaction is tiny and much smaller than using the existing remittances system.
2) With a bank, it's not even clear you could send $5 to Yemen as there's a civil war going on. And if you did find a money transfer company willing to do it, it would be very expensive. With Bitcoin, as long as the person in Yemen has a phone and can get online, you can send them any amount, it will cost ~$2, and take minutes to do.
1) The Yemen number is for the whole system. The energy to send one transaction is tiny and much smaller than using the existing remittances system.
2) With a bank, it's not even clear you could send $5 to Yemen as there's a civil war going on. And if you did find a money transfer company willing to do it, it would be very expensive. With Bitcoin, as long as the person in Yemen has a phone and can get online, you can send them any amount, it will cost ~$2, and take minutes to do.