Western Union struggles to maintain a "premium" price now due to competition.
The actual take on an average transaction from USA to El Salvador is way lower because El Salvador uses USD. So the only way to make money is on the Fee. (no foreign exchange revenue)
If you send $50, yes the take is high because there is a bottom to the price. But the average sender sends $200..$300 and cost, as a percentage, drops rapidly with the amount sent.
Many people thought bitcoin would destroy the remittance industry 10 years ago. It did not. People need money they can spend not bits in an exchange. Solve that last mile like Kenya did and maybe...
I don't think bitcoin can handle the transaction volume for the global remittance industry on the person to person scale for "money in minutes" service. It's a better fit for bulk transfers to pay the agents in foreign countries.
These are not wealthy people. The remittance is for real goods. The last mile with money is "can I buy stuff now". Some African countries are moving fast in this area with mobile wallets but it has been slow generally. Maybe this decade...
The situation is also getting better based on this report linked in Wikipedia:
Not in El Salvador. A quick Google search shows that:
A mid sized bank supports about 9 remittance companies. And a credit union supporting about 15.
It's less than that.
$ 400 million commissions / $ 24 640 million GDP x 100 = 1.66% of GDP.
I am not familiar with how revenue is shared between the remitting companies, but part of those commissions are set to offset the costs of operating the remittance network in El Salvador. Operating offices, armored trucks, complaiace, bank staff wages and security expenses.