Some countries have capital control and thus cannot send money from there easily. I lived in Vietnam for a while; there is lots of WU for people abroad sending

Some countries have capital control and thus cannot send money from there easily. I lived in Vietnam for a while; there is lots of WU for people abroad sending money there, but it’s really hard to send money out. But in the end expats usually just swapped the cash with each other and sent the money in Revolut. That worked (for small amounts anyway)