Benefiting from the dual-country BSL, there was a time when Crossair disappeared that the newly-upgraded airport was in danger of becoming a white elephant. Other airlines reduced frequency ... but thanks to EZS, the airport is still in business, a pleasure to use, and attracting new companies and routes as the years go by.
SXB, however, once heavily used as a military base, has seen better days ... even FR threw their toys out of the pram and removed themselves to FKB, and AF now serve Strasbourg/CDG by train, which makes any 'worldwide connections' far more time-consuming. Room for expansion already here ... but more takers welcome.