Why the degree requirement isn't universal
Most 'you need a degree to teach English' advice comes from Middle East and Korea/Japan style contracts, where immigration law ties the work visa to a bachelor's. That's real, but it isn't the whole world.
Countries like Cambodia have never made a degree a legal requirement for a basic work permit, and plenty of private language centres in Vietnam, Mexico and Colombia hire non-degree teachers for lower-tier contracts, even where the letter of the law is stricter.
