Why Eswatini said yes to US deportees

The United States has now struck deals with five African countries to accept deportees convicted of crimes. The individuals would not be sent to their countries of origin, but to a third country. Eswatini, formerly known as Swaziland, has already taken five men who are not its citizens. With Ghana, Rwanda, South Sudan and others signing on, what do these governments gain? And what happens to due process for the people caught in between?