That isn’t really true. Air stairs are still very common in much of Europe and Asia. It’s only places like the US and the Middle East that jet bridges are ubiquitous.
The software I wrote for them had to be legal to ship to every country except The Four, which created some new copyright scenarios I’d never dealt with before. When you’re trying to sell to 190 countries, you gotta be ready for a lot, and I’m not surprised that the external stairs are still a thing. Doubly so for a regional jet, which could be flying from all of your country to the nearest international airport.
