Narrow runway - bmi had been around since 1938. They only had enough money for a couple of weeks of further trading when they were sold to IAG.
Do you want the list of all the other airlines that have been around for 40+yrs that are no longer around?
I can assure you that the past is no guarantee to the future......now that is not a naive statement.......is it? You would be better thinking about current business models rather than when an airline was established.