Originally Posted by sports1

Probably has also to do with ongoing maintenance costs (techs, training, etc.)

As an aside, it's fun to see AC bringing in several ULCC planes as-is (Lynx 7M8) in seat configuration with ... 29" pitch and no recline. As a full service carrier. What a wonderful customer experience to be stuck on a 189Y for up to 6 hours. That's wild.