If you're underbanked you're probably not likely to be able to use or convert your BTC at the other end of the transaction, hence the value of that expensive "last mile" at Western Union or Moneygram. The exceptions the article discusses are the mobile money consumers in Africa, but here the conventional remittance fees are also a lot lower.

A quick apples to apples comparison suggests that converting sterling to Kenyan Shilling denominated M-PESA mobile money costs around 4-5% including forex and fees via Western Union and Moneygram (unlikely to be the cheapest of many providers in the marketplace) whilst sending to M-PESA via the BBC-advertised remittance services costs a 3% forex fee plus cost of obtaining Bitcoin (surprisingly expensive if your salary is paid in GBP; I'm struggling to see any options below 1%, and the cheaper ones aren't instant either).

There might be an advantage for the Bitcoin remittance services, but perhaps not one worth the additional inconvenience, delay and counterparty risk. Downward pressure on the major remittance firms' prices is always welcome, but given the relative lack of demand to convert in the other direction from KSH to BTC, the cost bases for these cryptocurrency enabled entrants into the market might actually be higher than the major remittance firms, especially if they grow...