BFS is very similar to Cork in respect of the city break market. Prague operated for years with Jet2, then also with EZY, then pulled completely. Berlin again operated for years and then pulled. Munich, Milan, Gdansk, Warsaw, Katowice all tried and all pulled.
Aer Lingus seemed desperate to operate to a destination that would return a profit for then, to complement their sun routes, and all failed which was such a shame. Like so many before, then they plumped for adding extra demand on the proven sun routes.
Now got to the point with BFS, that if an airline starts a route that takes your fancy, book for the first season, because changes are it wont return! You'd think with air travel demand lower and excess capacity, any profit is a bonus, so if a route is profitable, even not hugely, the airlines would operate and be thankful its not loss making, as discussed re Budapest, Madrid, Berlin etc above.