The use case is something like medical billing entry where people are trained to know all of the billing codes and they still use an AS400 green screen console.

The use case is something like medical billing entry where people are trained to know all of the billing codes and they still use an AS400 green screen console. The employees work by keyboard shortcuts and are extremely efficient, and every time someone tries to replace the AS400 with a modern web app, their productivity drops 100x. It’s the same scenario as a vim/emacs wizard vs a slick looking GUI that doesn’t have keyboard shortcuts.