Grow. We have many class G airports with RPT jet services and VFR traffic flying through the terminal area without survailance and without transponders. Ballina is an example. Don't even have a Unicom radio operator to report a plane taxiing on the wrong frequency as they all do for safety in the USA.
If we upgrade them to class E we get full Separation of all aircraft in IMC and also mandatory transponder so TCAS will work. But Bloggs is happy with the status quo at these airports because " that's how we did it in the 1950s and nothing must change"